Yea there are book stores, but unlike the libraries, they are useless too, actually Family bookshop which is located on Merqab street is quite useful. But Jarir doesnt have a good collection of book.
I recently ordered 3 books from Amazon.com, they got here safely, but it took about 26 days and that was the fast derlivery service. If it was regular, probably took around 2 months. You could even order from Barns & Nobles.