Try using
http://satoshibox.com. It is very easy to use all you need is upload your ebook and send your links to potential buyers. They can't download it if they didn't pay.
Also try cryptothrift.com I saw some books has been sold there.
seconding this , op should use all possible websites tho , will generate a better revenue : ) i also belive satoshibox takes close to no fee's while the other websites take quite some.