Tip: Do not use Discovery Education's provided citations, because they're incorrect. Here's a citation they provided:
Colman Communications, 2012. Three Branches of Government. [Video Segment]. Available from http://www.discoveryeducation.com
This is what the above citation should look like:
Colman Communications (Producer). (2012). Three branches of government [Streaming video]. Retrieved from Discovery Education database.
The library also has a tool that can help you figure out if a book is appropriate for a specific grade level. I recommend finding a few books that we have first, and THEN checking them in this database: