Okay, I'm having some trouble figuring out how to do this, I may have even read the answer and just didn't understand it. I'm still pretty darn new to the Creation Kit and making mods in general, so a lot of stuff still goes over my head lol. Anyway, I've more or less gotten the gist of creating and altering spells. Specifically, I'm trying to get the Vampiric Drain spell, or just make a new spell with the same effect but more powerful, to actually level the player's destruction skill when using it. I just can't figure out how to get it to do that. I created a new spell with the same effects as Vampiric Drain and altered a few things, but I still can't get it to increase my destruction skill.

Anyone think they can give me a hand? Or at least point me in the right direction to figure it out? I realize I probably sound incredibly dumb lol, but any help would be appreciated.

Look http://www.uesp.net/wiki/Skyrim:Leveling to get an overview of how skill leveling works and then look http://www.creationkit.com/IncrementSkillBy_-_Game for the papyrus commands you need.

Good lord, I didn't realize how far over my head this stuff would go lol. Guess it isn't as simple as it sounded in my head. All right, may just wait till someone else does it, or I'll try sometime when I actually have the time to read and watch all the tutorials I need to on scripting and whatnot. Thanks!

You need to adjust the Skill Usage Multiplier on the magic effect.

For example, i created a new conjuration spell and set the Skill Usage Multiplier to 100 (testing purposes only), and as soon as the summoned creature entered combat, my conjuration skill jumped from 20 to 34.

There are other figures which are also used in the calculation for xp, which are located under Character/Actor Values and then highlighting a skill. I would not advise altering these figures, as these would affect all spells in that skill. (These are the figures you see in the link posted by aellis)

Bear in mind that certain skills have certain criteria for xp to be awarded, in my above example i only gain Conjuration XP when my summoned creature entered combat.

Again the link that aellis posted is worth reading so you understand why and when xp is awarded.

I think he means getting a spell to level a different skill than the one used to cast it?

Yes the math is sort of complicated, but not that bad. The actual scripting isn't complicated. I might write a script for it later.