Project Gutenberg – Fabulous ebook site with over 20,000 free ebooks and 100,000 ebooks to buy. Most free books are available in HTML or plain text and you can convert to your own favoured format (I use Mobi pocket reader). 

Girl E Books – free ebooks written by women. Have some little known books as well as timeless classics.

Ebooks.com – site based in USA has many best sellers. Be warned though, some of the books they sell can only be sold within the USA (for copyright reasons). This is very annoying because, inevitabley the book I want I can’t get!

Fictionwise - similar to Ebooks.com

Regency Reads - Ebooks of previously paper published regency books.

Belgrave House – parent company of Regency Reads with a wider range of genre’s

Samhain Publishing – wide range of genre’s and sub-genre’s. Try not to be put off by the slightly scarey website

Moonlit Romance – small e-publisher of romance books