For avid readers there is a great site Goodreads. You can use it for various reasons. Either you want to talk about books with your friends or you can just use it as an inspirational tool to find great books to read.
After a simple registration, you are exposed to many possibilities – you
can browse in a listopia (lists with most read books depending on a genre), you
can keep track of all books you've read so far OR you can even set a challenge
for the whole year, meaning how many books you want to read in that particular
year (it motivates you to read more). And it's fun to see what others are
reading.
I'll start myself, here's my profile: