This is an incredible resource that is a compilation of data covering all sorts of aspects of American life- if you wonder how much time the average American spends watching TV, or eating, or the average amount of sleep an American gets... this is the place to go!
An on-going project to keep an archive of all that is available on the internet- while some items require membership to a particular library or payment, it is possible to filter results to only those that are open-source. This archive contains a wide variety of materials- ebooks, computer software, images, maps, movies, and more.
Teaching Resources: WWF has begun and open-source virtual classroom, which includes "Join Wild Classroom and check out a growing library of free animal and nature-related teacher guides, fact sheets, activity plans, and posters to help kids explore and learn about the world around them."
This site includes a handbook, videos and set of presentation slides that give instructions on how to apply the rubrics and use the online tool, as well as examples of what different ratings mean under each rubric. The information included in in the handbook, videos and slides is meant to mirror one another, with specific examples included in the handbook and slides.
This is a very straight-forward guide to a large number of OER databases. MIT is on the forefront of the OER movement, but this guide is pleasingly friendly for those new to the OER movement who just want some time to browse on their own.