google books is gonna be a great resource also....they now have ever issue of pop sci and Spin

Originally Posted by NeilShapiro

Sure there are all sorts of places to find free eBooks. The Project Gutenberg at Main Page - Gutenberg is a good place to begin. They have 30,000-plus free ebooks in all interests and many in various formats including ePub. Then you could try Feedbooks at Feedbooks | Food for the mind and they have many thousands of public domain books as well as books from new authors being shared. I also like the area at Mobileread at MobileRead Forums which also has thousands of public domain books. In the Mobileread Forums also check the "Deals, Freebies and Resources" section which often gives leads to free, copyrighted works that publishers are offering for download as PR. Good luck!

It looks like all the Project Gutenberg books could already be in the iBooks store . Source

I will be interested to see all the free books that will be available either in the iBook store or in the iTunes U bookstore.