So You Want to Be a Wizard — Diane Duane

Something stopped Nita's hand as it ran along the bookshelf. She looked and found that one of the books had a loose thread at the top of its spine. It was one of those So You Want to Be a ... books, a series on careers. So You Want to Be a Pilot, and a Scientist... a Writer.

But this one said, So You Want to Be a Wizard.

I don't believe this, Nita thought. She shut the book and stood there, holding it in her hand, confused, amazed, suspicious -- and delighted. If it was a joke, it was a great one. If it wasn't ... ?