Humble Bundle features several different types of bundles, now including books. Book bundles may include bundled ebooks, comics or audiobooks. *Unless expressly specified, these book bundles do not include physical copies for sale. If you are interested in checking out the latest book bundle (as available) simply click the Book Bundle tab at the top of Humble Bundle home page.
Such as with regular bundles, there will be multiple tiers. The top tier will display the content available for "pay what you want". Below will be the "beat the average" (in green) tier, and often there will also be an added "fixed price" tier (in blue).
And like all other bundles, you will scroll down to find your options for payment. Simply select your method of payment, enter in the desired amount, and adjust the sliders as needed.
As always, your contribution goes to helping out the publishers of these fine books, and raise money for the featured charities. Be on the lookout for what new & exciting books are presented on the Humble horizon!