PBS has lots of great stuff for science teachers- one of my new favorites is a set of educator resources at Nature. You can browse for lessons by: Topic, Animal, or Grade Level.
For example: if you search for grades 3-5 you find nine lessons ranging from Volcanoes to Eagles and Reptiles. Some lessons are Video-Enhanced lessons that relate directly to a Nature video clip. The lesson page contains pdfs of lesson worksheets, video links, and other related web sites.
Applications for Science Teachers: Life science teachers of all grades will find video clips and lesson supports that could supplement instruction, be used as homework, or provide opportunities for extensions.
Science for All 