Lesson Plans on the WWW, K-12

http://www.thegateway.org/
The Gateway to Educational Materials (GEM) is a one-stop source for high-quality Internet lesson plans, curriculum units, and other educational resources. It currently contains over 24,000 education resources. This extensive collection is categorized by subject area and grade level, and is keyword searchable. Each collection is reviewed and must meet certain standards to be included in the Gateway. Search results provide a comprehensive list of annotated links. Each record provides a "more info" option that provides the complete GEM review and gives a short description of the resource, including author, title, and location.