Kobo maintains their free books list pretty well
(goto
http://www.kobobooks.com and click on
Free eBooks at the top)
The newest ones appear first, so if you go every day you may find something you like. There are 7 new (to me) today, 5 from BakerPublishing and 2 others.
You can download the ePub (almost always DRM) and if you want to add it to your Kobo as a kePub you need to click on "Save for Later".