[Silverthornne]

Ok, Soul Gems for the masses, first edition:

To successfully steal souls within a gem, you need two things. One, you need an appropiate Soul Gem. Two, you need the spell Soul Trap.

Now, I don't know how many know this but most have probably found out by now (though it may be fixed in a patch to the game), but if a monster leaves a corpse behind, you can trap it after dead, you don't have to cast Soul Trap during the fight. So just kill it normally, and aim your Soul Trap on the corpse. There's a problem though, and that is that you cannot trap a humanoid within a Soul Gem (and I honestly don't know how that quest is so I can't tell you if it should work on that vampire or not).

The no target acquired message is one I only got whenever I tried to cast Soul Trap on a humanoid. I am not sure if you may also get it if you don't have a gem capable of accomodating that soul. In order to be succesful at your trapping, you need a gem of a value appropiate to what you want to trap. They go in the orders of petty, lesser, common, greater, grand, and Azura's Star. You can trap a rat on any of those gems, but you can't put a Golden Saint into anything but a grand soul gem or Azura's Star.

Once you have a gem that is no longer with any vacancies on it, you just drag it to your character portrait and you get the enchant screen pop up. Recharge item to give a boost to items that need it, create item to make a new one. The screen will be similar to the spellmaking screen once you choose to make a new item, you will figure it out easy. Just remember that if you make a weapon, you will most likely want the "cast when used" button to read "cast when strikes". With a gem of charge 400 or over, you can do "Constant Effect". Just train your enchant skill a bit by recharging items and get it to a decent number before making your own equipment as the failure rate can be frustrating. And an all around tip for anything you want to do, not just enchanting is that you have your best chance of success when your fatigue is at max for any skill. Low fatigue lowers chance for about everything.