X-link to the DRM-free thread for some programming-related Humble Bundle offers:
Humble Book Bundle Unreal Engine & Unity 5 presented by Packt contains DIY computer books for the titular game development software, as well as a video course and a free 30-day subscription to their Mapt service which apparently provides online reading access to their entire library.
Also, two of the Humble game bundles are offering sampler freebies with source code and concept art sketches, etc., for other games which you may be interested in looking at.