In particular, take a look at the Download Area . A large range of books for developers. Check Off The Shelf for the latest releases. Source code can be downloaded from the Sams CodeCenter Macmillan Computer Publishing Software Library Lots more source code here. In particular, take a look at the Programming Books .
Many titles have source code available for download.
Note that the files in the Sams CodeCenter are basically the same as those listed in the Macmillan Programming Books - only the presentation is different.