For this current set of books, entitled Bushcraft Survival Guide with a retail value of $400, Humble Bundle is offering up 31 books for $15 or more.
These books are not physical books, but ebooks. You can download them in .mobi or .epub format (some are also in .pdf format) to be uploaded to your Kindle library or other ereader.
This particular bundle’s charity is Worldreader. So the amount you give above and beyond the $15 price will go toward that charity.
In its first five years, Worldreader has reached 5.6 million readers in 69 countries with a digital library of 28,500 local and international e-books via e-readers and mobile phones.