Apple have published 6 free iBooks in iBooks Stores for Developers! The quality of the iBooks seems to be top-notched. It looks like how iBooks should be.
Although the books mainly attracts developers, but it seems to be a good first step for them to push the iBooks Store, and a good place for interested developers to start learning and developing for iOS. The titles are namely: iOS Application Programming, iOS Technology Overview, iOS Human Interface Guidelines, Object Orientated Programming with Objective-C, The Objective-C Programming Language and Cocoa Fundamental’s Guide.
You can download the eBooks from iBooks Store on your iPhone, iPod Touch and iPad. Although I hope iBookStore will be coming to the Mac soon! Would love reading on my Mac too!