kINDLE does not accept e-pub. It has to be in the Kindle format. You can get many free books though Amazon and also some bargains .99 cents to $2.99. That is the one negative with Kindles. There is a web site called Kindle Community. Here is website:
Kindle Boards - Index
Look under Book Bazaar and you will see a catagory
for Free Books and Bargain Books. Sometimes you can get some very decent ones, when they have promotions for new famous authors books soon to be released. These however last usually only a half a day at best.
But if you want to download library books via Overdrive, you will need to get a Nook, unless Kindle makes some changes in their next model, which I doubt. They do very well without it. When you download from the library, you only have two weeks to read book. Then it goes POOFF. If you didn't finish, to bad. This is not true with audio books, as long as you put them on your MP3 player.