Try http://openmetadata.lib.harvard.edu/bibdata
It's free, downloadable, and has records on almost 13 million items. Just going by the API (http://dp.la/dev/wiki/Item_API), it looks like it has the information that you need.
Project Gutenberg is my personal favorite:
http://www.gutenberg.org/
check out http://isbndb.com
http://isbndb.com/book/the_wind_up_bird_chronicles
Try http://openmetadata.lib.harvard.edu/bibdata
It's free, downloadable, and has records on almost 13 million items. Just going by the API (http://dp.la/dev/wiki/Item_API), it looks like it has the information that you need.