I have a Sony Reader (the PRS-505). You can get books from the Sony bookstore (which is hard to work with, and the books are often not well-formatted), from other pay-for-ebooks sites like fictionwise.com and manybooks.net.

In order to get them from the computer to your Reader, there's a couple of different ways. You plug the Reader into the computer with the cord (they give you one with the Reader, and it's a standard size connector so lots of people already have them), and the Reader shows up as a disc drive–you can just drop the books into the "books" folder in that drive, or you can use special software, like the Reader's eBook Library program, or Calibre (both are free downloads) to help manage & sort your ebooks into collections.

A lot of recent & popular books have to be paid for; many older books are available as free downloads. And some new authors are releasing their books as free ebooks, because they think free ebooks will encourage people to buy the paper book. (If you read it on the Reader, you probably won't buy it for yourself–but if you really like it, you might buy it for a friend, or tell someone about it, who might buy it.)
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you can fit alot of books inside

but if you do going to buy it then do plenty of back ground information on it so you know what ebooks are availble to buy.
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