Other
Pete's Power Point Station
For many people, Microsoft PowerPoint is the default for presentation software. This site presents a very large collection of PowerPoint presentations in almost all subjects and for most school grades.
Teachers.net
Teachers.net: Awesome Authors Lesson Plans
Not only will you find a description of a good unit, but you will find all of the handouts you will need including directions, letter home explaining the unit, websites to be used, and worksheets.