I am an on-line teacher at a community college. Can I use my internet expense as awrite off because it is required for me to do my work?

You can write off the PORTION of your internet use that is business related. If you ever get audited, you don't want to pay $100s in fines for the $15 (x # months school is open) in tax you saved by over-deducting household business expenses.

Yes, but how you will claim this and how much you can claim, depends upon if you are a regular employee or an independent contractor.