Do you know of a good book about magic and witchcraft?

Jinx by Meg Cabot

There is no such thing.

Jinx is AMAZING lol ..loved it!!!!

Other than HARRY POTTER, I would try the M.Y.T.H. series by Robert Asprin. They tell the story of an apprentice wizard and his teacher, a Demon named AAHZ. Plenty of humor and bad puns.

Harry Potter . . .

If I understand the question correctly, you are looking more for something like:
The Writer’s Complete Fantasy Reference put out by writer’s digest.
http://www.amazon.com/Writers-Complete-Fantasy-Reference/dp/1582970262/ref=sr_1_8?ie=UTF8&s=books&qid=1213758735&sr=8-8
Which was written as a reference for Fantasy writers and contains some interesting research into the history of witchcraft and many other things.

The Blue is for Nightmares Series by Laurie Faria Stolarz is reallly good
Blue is for Nightmares
White is for Magic
Silver is for Secrets
Red is for Rememberance

Hmmm haha somehow I don’t think the previous answers are exactly what you meant? I can’t think of any books off the top of my head, but if you’re looking for what I think you are (and I don’t know how much you’ve read already), you should try books written by Gerald Gardner and Aleister Crowley, since they, I believe, are strong influences on modern Wicca and witchcraft (especially Gardner, as he created the religion). If it’s kind of a more folksy thing you’re looking for, perhaps A History of Pagan Europe? (I can’t remember who the author is, sorry.)
Sorry I can’t help you anymore…try occultforums.com, most of the people there are very knowledgeable and there are lots of lists of book lists and stuff.

How to Turn Your Husband Into a Toad by Mildred Masser

Here are my book recommendations for learning more about the history:
http://www.amazon.com/Triumph-Moon-History-Modern-Witchcraft/dp/0192854496/ref=sr_1_11?ie=UTF8&s=books&qid=1214494495&sr=1-11
http://www.amazon.com/Encyclopedia-Magic-Witchcraft-Susan-Greenwood/dp/0754805816/ref=sr_1_3?ie=UTF8&s=books&qid=1214494565&sr=1-3