Here are some general useful resources for math teachers.
- Geometers Sketchpad Sketch Exchange - a great resource for pre-made Sketches.
- Math Illustrations - a lot like Geometer's Sketchpad with some nice annotation features. Works well for making images for class handouts.
- Padowan Grapher - Great free graphing progam that works nicely when integrated with MS Word.
- MIT Open courseware -
Excellent source for video courses from calculus and above.