Using data from an external database.

We're in the process of setting up a social network for comic books and would eventually like to set up a Marketplace to sell and, possibly, trade comics. Ideally, we want to keep as much information the same across books as possible and would like to use data from the Grand Comics Database, which makes it's data available under a Creative Commons License, to that end.

We're aware that this is a daunting task and will most likely require some custom plugin or scripting but we were wondering if anyone here has done something similar and/or had some pointers they would like to share.