Conjurer

Conjurer's have no limitations to their advancement except experience. All the basic knowledge for major advancement is held within the book series, "The Greater Key of Solomon" and "The Lesser Key of Solomon". Being careful and being sure to ask/command properly is the only true difficulty. Acquire these books, both series of which are available online, and read them thoroughly. These are all a conjurer need. Perhaps later, depending on your own personal alignment, the Grimoirium Verum (black arts) may be desired. I have heard also, through a fairly good source, that A. E. Waite's book, "The Book of Black Magic and Pacts" is a good read for the aspiring conjurer.