You don't have to do the quests in this order but you might aswell.

Quest 1 - Soul Brothers

This is the newbie quest. The ultimate in easy quests. Ok all you have to do is go to the Gateway of Dreams and listen to the Soul Brother. If you haven't already agreed to obey the Golden Rule you have to do that first, simply by answering "yes" when he asks. After he has finshed telling you about the meeting go south/down to MacGuyver Castle. Go to the well and you will automatically tell the soul brother about the meeting. Your reward is a whopping 1000 gp.

Quest 2 - Professor J

In MacGuyver Castle above the amulet store is a BOOKSHOP. Go to the bookshop and listen to the man, he'll tell you about Professor J. Leave MacGuyver Castle and go north/up to North Umbrage (it's the northern most town on the main map). Go to the building to the east/right of the entrance, it is Professor J's place...excited yet??
He'll ask you if you love books as he does, answer "yes" and listen to what he has to say. Return to the bookshop in MacGuyver Castle(you'll need 1000 gp) and purchase the book the same way you would buy equipment. Once you have the book return to Professor J in North Umbrage and it is complete. Your reward is the stun spell.

Quest 3 - The Dragon

In MacGuyver Castle head north/up to the top of the Castle and you will find the King in his throne room. He will ask you to kill the dragon. The Dragon is really just a Fire Wyrm, it is level 50 so if you can't kill a lvl 50 monster yet you'll just have to wait. Go to the cave south east of MacGuyver Castle, it is called the Wyrm Cavern (I can't really remember but it isn't important). The easy way to do this is to type /terrain (this will NOT mark you as a cheater).
Now that you can see the terrain you can see the opening in the cliffs that wasn't there before...magical eh??...work your way down to where the fire wyrm is in the bottom right of the map. He'll talk a little, then he'll leave and come back in a fight scene. When you beat him you'll get the scales you need (They won't show up in inventory so don't look). Exit the Wyrm Cavern and go back to the king in MacGuyver Castle...he's an ungrateful lil SoB. Go to the shoe store in MacGuyver Castle and a thief will steal the boots that are made for you. Go back to the Wyrm Cavern, this time go to the thieves hideout in the bottom left of the map.
This battle is harder than the fire wyrm so make sure you're up for the challenge, it is about 4 lvl 50+ nature monsters. After you kill the Thieves the quest is over. Your reward is a pair of Fire Boots. Now you can walk all over Inferno.

Quest 4 - Gregors Quest

East of Wyrm Cavern and just at the top of the Lake on the main map is a cave. This is Gregors Cave. Enter the cave and Gregor will ask you if you are the saviour, answer "NO", he'll ask if you want to hear his tale, say yes. He gives you some story about a scroll. Leave and go South East till you come to a skull shaped place called Mouth of Satan. Enter it and this guy will ask you if you will attempt his riddles, say "yes".
He asks a series of questions - these are so bloody simple and only require common sense, for that reason I'm not going to give the answers. If you get them wrong you deserve to die fighting the monsters that attack you. Ahhh what the hell for the incredibly stupid here are the answers (don't expect the questions to be word for word or in the right order).

1) Does your soul have a color? - "yes"
2) Do birds know why they sing? - "yes"
3) Does a mountain dance? - "no"
4) Is my favourite color green? - "yes"
5) Did you cheat? - "no"

Once you have answered all the questions correctly or defeated the monsters after getting the questions wrong the enchantment over the Pyramid/Library is lifted. Go to the Pyramid/Library and an old lady gives you the scroll. Return to Gregors Cave and he'll ask you if you're the saviour, answer "no" and the quest is complete. Your reward is the Soul Amulet.

Quest 5 - Goblins

Go North east of Gregors cave to a town called Hampton, there some guy will tell you about the goblins. Go east from here to the Goblins Camp, the goblins will blame you for the theft of an artifact. Go south and you'll find 3 trees on the edge of the water, this is the goblins hidden camp. Here you'll find out that a goblin stole the artifact.
You'll have to fight a few goblins and goblin warriors and 2 goblin centurions which are lvl 80 so you'll need to be fairly high in levels to beat them. After you kill them, return to the Goblin Camp and the goblins give you your reward which is the Soul Helm.

Quest 6 - Dolphins

Go west of MacGuyver Castle to a town called Westin. Here you'll find a pond with Dolphins in it. Listen to them blab on and on then leave and go to the east of the main map, go south west of Satans Mouth and the Library along the coastline you will find another pond. A Flamingo named Torch will talk to you and ask if you want this, say "yes". Return to the dolphins in Westin and the dolphins will go on and on again.
They give you some rubber boots and tell you that you need water boots and that the eels have them. Go South East from Westing till you get to a light house building, This is the Isle of Light. Go west in here to the eels. You fight them and get the water boots, there are 2 eels and 1 parasite to fight. Now go east on the main map into the Ocean where you will find Sea Grotto. Go south and talk to the king, then go north east and talk to the jailer.
Return to the dolphins, heres another big fight. After you win they get arrested. Go back to Sea Grotto and talk to the king, he'll tell you that the dolphins are innocent. Go to the jailer and you'll have to fight him and other stuff...all pretty high level, quite a tedious battle if you only have "all spells". Once you beat him go back to the King and the quest is completed. Your reward is the Soul Horn.

Quest 7 - Quest for Fire

North East of the Gateway you will find two wolves. One is sick and they talk about some rubbish. Leave and go South West to Springwell. In Springwell go west to the a house. This is the Veterinarians house. He'll say he doesn't have any wolf medicine. Go back to the wolves and they will tell you about Inferno. Go South East to Inferno, then go go south and you will find some guy who wants to make fire. He'll tell you about needing a lens.
Leave inferno and go North to the Mint. Listen to the guys in the Mint, they're lost. Leave and go back to the bookshop in MacGuyver Castle. The bookshop guy gives you a sample page to an encyclopedia...wow it's the map. Go back to the Mint, you'll have to fight a lvl 55 spider. After the battle the guy gives you his monacle AKA lens. Go to Inferno and the guy will tell you that you need kindling. Go to Animal Kingdom, then go east in there till you find a beaver complaining about it's sore tooth. Leave and go back to the Vets place in Springwell, you'll have to fight a Harleking it's like lvl 60 or something.
When you beat it the Vet will give you some powder for the beaver. Go back to the beaver and he'll give you some kindling. Now go back to the guy in Inferno and he'll show you how to make fire. Then go to the wolves and it's all done. Your reward is the Soul Bow.

Quest 8 - The Princes

Go north along the coastline from the Gateway and you'll find 2 princes argueing. Listen to them for awhile. Go to MacGuyver Castle, go up and before you reach the Throne room go right and then down to a building/The Treasury. In it there will be a guard. He'll tell you some stuff.
Leave and go back to the Princes. Listen to them again for awhile. Then go back to MacGuyver Castle now this time go to the building to the right of the Treasury and you'll find a Goblin, you'll have to fight a few goblin monsters here. When you win stay in the scene, the goblin will come back out and talk a bit, then leave. Go back to the treasury and it is finished. Your reward is the soul armour.

Quest 9 - The Gladstone

Go South west of MacGuyver Castle to a place called Roundtree. In Roundtree go to a big building there called Fort Roundtree. The King and Queen will tell you some story about a with and the Gladstone. Leave Roundtree and head East to a place that is under and just before Animal Kingdom (yeah I know...not great directions). In here you'll find Miranda, she'll ask if Queen Jett sent you, say "yes", she'll tell you a story and then you'll have to fight a lot of little monsters.
When you win she'll tell you where to go. Leave and head east. Go south of the Rune Ruins to a big tree. Here you will find the Gladstone, you'll also find a lvl 115 Giant Slobber. When you kill it the Gladstone is freed. Return to Fort Roundtree and the quest is finshed. Your reward is the Soul Sword.

Quest 10 - The Long Tedious Yet Important Quest

Before you start this quest you'll need to have the Frog Boots from Quest 6 and you'll need to have done Quest 9. Ok go to Springwell, when you get there go to the trees just to the west of the entrance. Not sure if you have to be wearing the frog boots or if you just need to have them but you might aswell put them on before you go in anyway.
Inside a frog will tell you his sad little story blah blah blah. When he's done leave and go east to Animal Kingdom. Go north to you get to a big house. Listen to Glannon cry and moan, when he's finshed leave and go West and a little south to another house. Listen to these people then leave. Go North East till you see a castle surrounded by water. Use the Frog Boots and go on in. You tell the king about his son and he tells you that you need Elven Booties. Go back to Glannons place.
Leave Animal Kingdom and go South to Port Shrimpee. In here go to the 1st building to the east. You'll cut the princess down with the Soul Blade and she'll tell you a story. Go back to Glannons and listen to everything when he's done go to Snorts to the west and when you're in there say "Glannons dead". He'll say you need proof.
Go back to Glannons and listen to him ramble on again in his slow way and he'll give you the Elven Booties. Head back to Snorts place and he'll believe that Glannon is dead and unlock the gate. Go North West of here till you see a castle. Use your Elven Booties to get to it. Once inside listen to everything the witches say (they use a magic word SHAMBOLA) then kill the lvl 110 Wyrm. Once the witches have finished talking go back to Glannons place.
Listen to them talk and leave when they are done, go back into Glannons and he'll say he's going to Snorts. When She's finished talking to you go to Snorts. Snort will be roaring and will say that a magic word "pickle" makes you roar loud. Leave and go back to Glannons. Listen to them talk and Leela(or whatever her name is) should send a token to Lyssa (the princess yo cut down).
Leave and go back to the frog in Springwell. Use the magic word SHAMBOLA when you get the option, then use the magic word PICKLE when you get the option. After he has left go to the Gecko Castle in the top right of Animal Kingdom. Listen to them talk and he'll send you back to the witches. You'll have to fight another Wyrm and when it is dead the witches give you the Soul boots.
Leave Animal Kingdom and go back to Princess Lyssa in Port Shrimpee, she'll talk a little and say she feels like she's something else. You'll get the option to say something again, say SHAMBOLA, she turns into a cat. Leave and go back to the Gecko Castle in Animal Kingdom and the king tells you his son left. Leave and go back to the Princess in Port Shrimpee and the quest is done. Your reward is the Soul Ring.

Quest 11 - PokeGod

Ok the 1st of the not really a quest, quests. You'll need a fairly strong pet before you do this. Just get a Goblin Catapult. Go to Westin and from there got to the bottom right hand corner of the map. The gate on the right takes you to the Pet Arena. Go to the top right of the map and thats the pokegods place.
Your pet will need to fight a number of battles to earn badges 1-10 (I think). The higher the badge no. the harder the battle. The final badge has a lvl 125 Revenge and a lvl 100+ monster. The best thing to do is raise your Gob Cata's stats during the battles and to heal it when it needs it. It's more tedious than it is hard.
Once the pet has won that final badge you get the Soul Shield. You also get to choose a Master Pet. These are just level 80 pets that you can't catch in the game. They are Fire, water, earth and air, simply need to say one of those to get the pet. I recommend Fire and Water but you can go back and do this over and over again to get them all.

Quest 12 - Challenging Battle.

This is the only really hard part of the game and it is the 2nd of the not really a quest, quests. You will need to be lvl 100 to do this, even then it is based entirely on luck (Whether the 5 Giant Dwarves cast/hit alot or just mess around). Smart people will take a pet or a friend in to do this one with them.
After Killing the Sand Wyrm the SandMan will show up and he'll give you the Soul Fist.

Thats the end of the Quests, the rest of the Soul Gear is in the top right of the Rune Ruins in the "hidden" buildings AKA Lord Fists place.