Humble Bundle is currently offering a wide range of books from the Make: catalogue. At the moment over $300 worth of books is on offer.
The offer expires in 7 days.
The deal is you pay what you want, over a very low limit, some of the money goes to charity, some to Make: and some to Humble Bundle; you can choose these ratios.
What you get is DRM-free e-versions of the books in pdf, epub (Apple iBook) and mobi (Amazon Kindle) versions.
There is a number of (IMHO…) highly recommendable books in the offer. What more can I say?