Edutopia, the George Lucas Educational Foundation, is an excellent resource for educators. Their site has a huge variety of resources, tips, and research on education and is accessible for free. They are a big proponent of Project Based Learning (PBL) and also have a lot of resources on best practices in education.
They have a tremendous amount of resources on Project Based Learning available for free on their site.
Resources include lists of reading materials on PBL, links to schools that are using PBL, Resources from Edutopia on PBL, Resources from Maine on PBL including examples of PBL, lesson plans, assessments for PBL, planning guides for teachers and schools, professional development resources, resources for parents, and links to organizations and other resources on PBL. (Resources are in PDF form).
Project Based Learning is a great way to teach content, as well as essential skills such as teamwork, collaboration, problem solving, and more.
This is an excellent collection of resources about PBL and how to implement it in your school and classroom.
More free classroom guides for educators from Edutopia
Project Based Learning Resources for Educators
WPI Plan - a great educational model for all schools
10 Important Skills Students need for the Future
"Lehr und Kunst" or "Theory and Practice." - what we strive for in education