Flexbooks is an intriguing site. It is a collection of editable, customizeable online textbooks that are FREE! While the collection leans towards science, it does contain content for other classes. This collection allows you to:
- Create and publish your own content from scratch
- Choose pieces from several textbooks in the collection and put them into a new textbook.
- Edit the content in any textbook to suit your needs
- Reorganize any textbook to work better for your class.
Advantages to this? Several:
- Cost is nothing.
- Textbook can be posted online
- Textbook can be saved as a PDF and loaded onto laptops for students without internet access
- Students can use Text to Speech to have the textbook read to them
- Textbooks can be printed as needed
- Textbooks that are posted for the public are reviewed by the ck12 site.
I haven’t explored this, but perhaps students could create reference guides as well. The site has a good “View the Demo” video (7 minutes and worth the time) that goes over the features. Give it a look.
Teacher Tech 
I really think that Flexbooks are the way that curriculum should be distributed. It makes sense to be able to mix and match text to fit your student needs for the year. These may look different from year to year. Brilliant!
Awesome alternative to more costly paper.