97 Ford Contour will not crank

I just bought this Ford Contour yesterday, it ran great for miles and several ignitions worked perfect. Today, the car suddenly will not crank (the engine will not start), but it turns over and lights/radio/air/dinger all come on, just no ignition. I found out the battery was bad so purchased a new one and still no luck. I need help ASAP, I have school tomorrow and two kids who also rely on me for transportation and have no other vehicle. We checked out a lot but still can't find the exact problem and it just happened literally overnight. Please help. The details include: when cranking the ignition with key, it makes a clicking noise but no engine starting, and also the clicking noise is coming from the fuse box under the hood so I'm not sure if it is that or the starter. All of the fuses in the interior (lights, radio, and such had to be replaced because they didn't work but now do). I have not replaced the under the engine fuses because I don't know which goes to what. Any quick info would be greatly appreciated, thanks guys. BTW my name is Kristinia. Thanks. Help!!!