I am in need of a wiring diagram for power windows for a 2000 nissan altima. Is there anywhere that I can get one free of charge?

Free? Check your local library. If they have some auto repair books, you may find one that applies to your model year.

Otherwise, your local parts store will probably have the manual you need for a relatively low cost. Bonus: you can use the rest of the manual on the rest of the car. It will eventually pay for istelf in savings, IMO.