Also, just a bit of advice - not having competitors can be bad. It could indicate that you're trying to build a company in a market which can't exist because it's just not viable.
whatshouldireadnet.com reader2.com shelfari.com and of course Amazon
What they do not do is give you an orderly list of books and an order to read them in to maximize knowledge and avoid excessive repetition.
I was thinking of having it controlled through votes, up and down. So a user who just obtained say an IT certification such as the CISSP can list the books he read and the order for the search term "cissp". Then if one of the books is heavily downvoted it would be removed from the list. This way dated material will be removed and replaced with up to date books.