Where can you create spells in oblivion?

First you have to join the mages guild then keep doing quests until you are accepted into the arcane university,i dont exactly know where to find the spell making altar but i do know somebody will probobly tell you(excuse my spelling and hope this helps)

There are 2 places you can make a spell. The Arch Mages Quarters and a building on the far right of the Arcane Univercity.