Web 2.0 Guru has a great site with a listing of Web 2.0 resources for educators. It lists the resources by category, with links to the resource or more information.
The top of the page starts with a list of the top 10 Web 2.0 resources every 21st century classroom should have. What's great is that most of the resources listed on this site are free.
Take a look around the site and explore what's out there to help you improve teaching and learning in your school and classroom.