I’m rubbish at choosing books to read, so recommendations from friends who are better read than I am are very useful. I enjoy using last.fm as a way to discover new music that I might like, so thought I’d look to see if you could get the same for books.
I’ve found two sites that I quite like:
goodreads
This is a lovely site. Track the different books you have read, and are reading. Sort them into different “bookshelves” if you want to group them.
It’s got a ton of RSS feeds, and it’s focus absolutely seems to be to make it easier to track what your friends have read and are reading, what they like and don’t like.