Just released two weeks ago, The Penguin Book of Witches covers all matter of historic information on witches. Beginning with Witches in the Bible and witches in England, it continues through the early US colonies, then focuses on Salem in particular. The final chapters are on what happened "After Salem."
Read NPR's book review: "The Penguin Book of Witches Casts a Sobering Spell."
You can also check out an excerpt at Huffington Post.