OK… you guys are going to love this…

CK-12 Foundation

CK-12 Foundation FlexBooks

CK-12 Foundation is a non-profit organization with a mission to reduce the cost of textbook materials for the K-12 market both in the U.S. and worldwide. Using an open-content, web-based collaborative model termed the “FlexBook,” CK-12 intends to pioneer the generation and distribution of high quality educational content that will serve both as core text as well as provide an adaptive environment for learning through the FlexBook Platform™.

What’s that all mean, you ask? In a word: free books! (Ok, two words!) As CK-12 puts it:

Traditional textbooks are both expensive and rigid. FlexBooks conform to national and state textbook standards. They are free, easy to update and easy to customize. With FlexBooks, you can customize your textbooks to support your innovative work in the classroom. The CK-12 Foundation provides FlexBooks free to anyone who wants to use them.

You can download these FlexBooks (PDF, iPad and Kindle). Create an account at CK-12 and you can create your own FlexBook by dragging and dropping chapters that you want before saving and printing.

Totally awesome and totally free.