Okay, so I have been looking every where for the Invisibility Spell Tome. I went to the College of Winterhold and they didn't have it. I don't know where else to look. So can some one point me in the right direction? :shrug:

Atub in Largashbur (Expert)

Drevis Neloren in the College of Winterhold (Master)

According to http://www.uesp.net/wiki/Skyrim:Illusion

But you do have to be level 75 for Drevis (Don't know about Atub)

Only catch Drevis in the college library, ot is the only place he seems to mentally focus

They will only stock it when your Illusion skill gets to a certain level. You won't be able to even find the tome for Invisibilty until your Illusion is around the mid 60s.