In response to Denise Keogh's request for places to find great books, I recommend the Choices lists. Provides some great titles for children, teachers, and young adults
Great resource to find science books for the library or classroom. I have purchased several from the list (or received via Junior Library Guild). Their recommendations do not disappoint.
You can simply use this site to find books in a series, but if you register, you can also create a public profile, and be notified when new books in certain series become available.
Very comprehensive site that has many useful features, including daily podcast booktalks. I often suggest the site to teachers looking for books of a particular genre, theme, etc. Some of her pages that link to this are now wikis.