Google has some awesome, free resources for educators to use. I use iGoogle, Blogger, Google Sites, Google Docs, Calendar, Gmail, and much more as an educator and with my students. Google had a big presence at ISTE11 and there were some great presentations and resources on using Google Apps in Education. This site has a list of the presentations and links to the resources. If you use Google or are thinking about it, this is a great place to start.
Google Apps for Education at ISTE11
Google for Educators
iGoogle as an organizational tool for Educators
Google Apps for Education - Guide to Going Google
Google Mobile Apps