The Environmental Literacy Council has been dedicated to helping teachers, students, policymakers, and the public find cross-disciplinary resources on the environment. An independent, 501(c)3 organization, the Council offers free background information on common environmental science concepts; vetted resources to broaden understanding; and curricular materials that don't tell teachers how to teach, but give them the tools to augment their own backgrounds - no matter what their current knowledge.
The Conservation Education Strategy Toolkit contains resources developed by the Association of Fish and Wildlife Agencies (AFWA) to support conservation educators.
Includes lots of useful stuff: downloadable lessons, "Benchmarks for Conservation Literacy," "Field Investigations: Using Outdoor Environments to Foster Student Learning of Scientific Processes" etc.
Signals of Spring-ACES captures the interest of middle and high school students. They learn formal science, but in the context of the ocean. Uses activities with NOAA remote sensing data improves environmental and ocean literacy.