A great place to start would be the literature guide on this site. Here's the link directly to that:
There are also lots of other guides available on the web. Here are a few you might want to look at:
If you use any of the information from the summaries or study guides in your work, be sure you cite your sources so you don't plagiarize!
Here are some online quizzes/tests that you can use to help you study:
If you're trying to improve your comprehension skills, a better way to study would be to use comprehension strategies as you go, rather than trying to use quizzes and summaries. One strategy is SQ3R. It's usually used for reading non-fiction text (like textbooks), but can work great for literature! Here's how you do it:
SURVEY. First, look over the chapter. Maybe flip through the pages and read three or four sentences from different places.
QUESTION. Ask yourself what the chapter might be about. Make a prediction.
READ. Obviously, read the chapter.
RECITE. After you finish reading, retell the chapter to yourself, aloud. You may also want to write a quick summary of the chapter or draw a picture or two to represent the chapter. Be creative here.
REVIEW. After each chapter, quickly look over your notes and tell yourself what each chapter was about. Do it quickly - don't take too long! At the end of the book, you should have a pretty good knowledge of what happened in the story. The more you review, the more you'll remember.
Hope that helps!