science buddies offers science project ideas, blogs, teacher help, lesson plans and careers, and much more. Every science teacher can usable content at this site.
This is a great site for anyone looking to create a static website using wordpress. The site offers step by step instructions on how to get your site up and running.
Mr. Black's World History Page contains an entire year of World History class content within one site. This site contains information, lesson plans, hands on activities, and more. A teacher could use this site to teach an entire year of World History without going anywhere else for another resource. If you do use the site just give Mr. Black credit he obviously dedicated a serious amount of time creating this site.
Pete's Power Point contains hundreds of free Power Point presentations on all core subjects for both primary and secondary educators. All of the Power Points can be downloaded and used as is, or you can alter them to fit your lesson and teaching style.
The Science Spot is a one stop shop for free lesson plans, resources, worksheets, hands on activities and numerous other resources. If you teach science this site should be on the top of your favorites list. The quality of the materials and resources on this site are excellent and best of all it is free.
The History Teacher's Channel provides great historical content set to some of America's most popular songs. Think of it as and educational version Weird Al Yankovic. Every song and (and there is over 50 to date) contains a music video that reinforces the song. I often use these for anticipatory sets in my class, and the students love them. Best of all they are free.