I got both a Kindle and a Kobo for Christmas. I took the Kobo back, hated it but love the Kindle. There is also a website that offers free books for most readers, believe it's www.noob.com. If that isn't it PM me and I'll send the link along to anyone who wants it.
I've downloaded several books from that site and they were free. Some you have to pay for but most you don't. I'm loading up my Kindle for my hip surgery next month.