Someone just directed me to a great site called "Fantastic Fiction". It's a great source of bibliographies and book information.
If you're looking to fill out a collection and need some titles this site is a great one for that! If you sell books..you can't miss this site too.
For example, I sometimes sell lots of Nancy Drew books. Fantastic Fiction has the entire list of titles. What that will save me in typing!! I wish I had found it sooner!
Anyway, just a great tip for you!