NSTA RESOURCES
Below is a link to an National Science Teachers Association collection of resources. There are articles, chapters, professional development, and lesson plans that would be helpful when creating a unit on seasons in a K-2 classroom.
http://learningcenter.nsta.org/share.aspx?id=8m0tpfZw8U
http://learningcenter.nsta.org/share.aspx?id=8m0tpfZw8U