An explosion of good books
When I was an MS Developer I was always a sucker for WROX press books as they were usually the best layout for me as a seasoned programmer. Even though laid out from a learning perspective, it still gave me the ability to jump around and just look up the important stuff I needed, having real world examples.
Now that for the most part I don’t use Microsoft Technologies (out of personal preference) I have clung to a new publisher that specializes on the other (or open depending on how bitter you are) side of the fence. The publisher is called The Pragmatic Programmers and they have an extensive list of great books on Xcode, Cocoa, Core Animation, Core Data, Ruby, Expression Engine (which this blog runs on) as well as a more topic based books like Unit Testing, Version Control, Interface Design. In addition to books, which are instantly downloadable, they also have a free audio area and a pay per lesson video area.
So whatever your side of the fence, both of these publishers offer great learning material over different medias. Now go and get your learn on.