My car won't start now - rev count dropped to zero, now it won't fire

I know next to nothing about cars - basically I'm trying to prepare myself for the worst for when I get it to a mechanic, so that when/if he tells me its going to cost an arm and a leg, I'm not going to embarrass us both by crying in his workshop! What could be the likely cause? (No point in trying to tell me how to fix it, haha! I wouldn't have the first clue!)

I filled her right up the day before - So before you ask me (like my insurance company did - argh) petrol is a-plenty!

Thanks and apologies in advance - being so clueless when it comes to cars is definitely not a good thing.

Thanks for replying - as soon as daylight comes in my side of the world I'll check fuses. As for the rest of it, I wouldn't have a clue where to start!

That would be great - thank you for your help. When I get told what it is + the cost, and on the proviso that I don't have a heart attack, I'll definitely take you up on that!

(Sorry for wasting your time with absolutely no info either!)