16 OER you can use for any course

16 resources that offer a wide range of content and tools that can be used in any course, according to the latest publication of Campus Technology.
here is a list, but I encourage you to go to the post as it has a brief description for each resource. And Campus Technology is to come up with full guide of Open Ed Resources (OER) this August.

College Open Textbooks
Learningpod
Lumen Learning
MERLOT II
MIT Open Courseware Online Textbooks
OER Commons
Open Course Library
Open Education Consortium
Open Learning Initiative
OpenStax CNX
OpenStax College
OpenTextBookStore

Saylor.org
Spiral Physics
Teach Astronomy
The Orange Grove