2000 Other Saturn Models won't start

Well, it's hard to say since so many things could cause this but, I would caution you against assuming the battery is good just because a radio works or the pump is on. These units require much less draw than what cranking a cold engine would require. It is entirely possible that the battery has enough juice to do these things but not start the car.

Ist thing: ensure the battery is fully charged and capable of delivering the necessary amps - you can't just check the voltage and say it's okay. If it is not the battery, you need to do a methodical inspection of your ignition system including ensuring all cables and connections are solid.

A reputable repair manual is invaluable if you decide to engage in this endeavor. Good luck!