If you're looking for free online books written by mostly dead people, check out ReadPrint. The site says they have thousands of free books for students, teachers, and the classic enthusiast. That may be true, but they don't have Nora Roberts or J.D. Robb books, so I know one reader that's probably not going to be bookmarking Readprint any time soon.
(Note: My crack research staff tells me that the books were written by living people who are now dead…we think.)