Witches don’t really use spell books other than those they write themselves. Check the New Age section in Barnes and Noble. Ray Buckland and Scott Cunningham mostly write about Wicca, which is not quite the same, but they include facts about witchcraft too, and they’re pretty good sources. Stay away from Silver Ravenwolf though. Her books are not good sources, and she claims that Wicca is witchcraft, which is not true. There are many other good resource books in the New Age section, but I’m not really familiar with other authors. Look around. The internet has a million different sites, legitimate and non-legitimate. Basically ignore anything that says that you can do magic instantly, or sites that tell you spells are just little poems that make things happen. Also, avoid sites that say that you can inherit witchcraft, because practicing witchcraft is a choice, you aren’t born with it. And, finally, avoid sites that claim witchcraft is evil. I hope this helps.