Ditto on the Free Library, though I'm also a monthly subscriber as well, six books for the price of a paperback, DRM free so I can read it on anything, pre-made into formats compatible with any reader or even just pure HTML. Highly recommend them, if you like SciFi.
Have you read the 1632 series? Love it, and so does the wife. Of course, since we’re addicted to the series, we end up buying the hardbacks. If I had a netbook, I’d probably go with the electronic versions.