So, I recently rebuild one of characters. Until level 36 he was a vampire lord, but since this whole vampire thing is not really my cup of tea, I decided to rebuild my character in to a necromancer. Only thing is I have absolutely no idea what a necromancer is or does and I could use some guidance about being a necromancer, RolePlaying wise and well otherwise.

Necromancer: Death Magic. Poisons and undead minions are your stock and trade. Any Conjure Undead spell works wonders here, as well as Destruction Magic.

The reason to become a Necromancer is varied and personal. Some are glorified Grave Robbers, who get their kicks off exploitation of the dead. Others are scholars, looking to probe and test the limits of the flesh. Others still seek dominion over man in the cruelest of senses - "collectors" of their mortal enemies.

The ultimate mystery and triumph of a Necromancer is the transcendence of spirit from flesh - the attainment of Lichdom.

Which spells could boost my conjuration fast?

Spamming Soul Trap on a dead body.

Oblivion does a great job of defining necromancy in its Mages' Guild Quest. If you ever have time for it, give it a whirl. That is, unless you've already done it.

Are you refering to the game Oblivion? I have it on PC, totally hate it.

@Shadow Titan

For some bizar reason, that sould trap spell never really worked for me. Which is why i always do soultrap enchentments on weapons and bounded swords.

The spell only works at close range.

I'd recommend Shivering Isles also as there's quite a good amount of necromantic culture (particularly toward the middle of the questline), but I can see you wouldn't care too much for that!