I'd like to share my addiction with you so I'm not alone on the dark side of literacy. These are my favorite dealers for my drug of choice:
http://www.pixelofink.com/
Inspired Reads
http://www.inspiredreads.com/
eReader Love
http://ereaderlove.com/
I also have an Amazon Prime membership, which allows me to borrow a book for free every month. They also have Kindle First, http://www.amazon.com/gp/digital/kindle/botm which spotlights four new or pre-release books each month, and you can choose one for free. If you don't have a Prime membership, you can get one for $1.99.
No Kindle? Use a the free app!
http://www.amazon.com/gp/feature.html/ref=sv_kstore_3?ie=UTF8&docId=1000493771