I am in the process of setting up an ISBN database which I need for a price comparison site for books. As there doesn't seem to be a CDDB for books I'd like some ideas/pointers to how I can collect the ISBN information to get the database started - and then how I can keep it up-to-date - in the easiest and cheapest way!
I'd prefer to collect the information in a MySQL database, but if there are solutions for other databases I'm more than willing to take a look at these too.
Any help is appreciated. Thanks!