Here at the EnglishBook we don’t really tend to highly endorse the study guides that are available on single texts, especially those of the generic USA variety designed to help college kids with their SATs or something.

But, they play a part, and can be useful at times, when you’re checking your knowledge, refreshing your understanding or looking for some good words. As long as you keep them in their place and never use them to try to replace developing an understanding of your own!

Shmoop’s CRUCIBLE pages seem to have some good material, and nice hyperlinks to some of the background knowledge you might find useful. Just remember to read the book as well!