2000 Honda Civic Timing Belt

My 18 year old daughter's car that she drives VERY hard, turned off on her one day and she claims the only thing she noticed was a small oil leak. When I checked it, the oil level was about a quart low. The engine does crank and it almost wants to start but doesn't. Have been told by a friend that the timing belt might have busted or has probably jumped from it's original position and needs to be replaced. Want some advice on how much this will cost and is it something I can do myself? I have done all work on this vehicle myself so far. I do not mind taking it to a mechanic but I would like to know what I am getting into. What other problems may I encounter with this? I have heard from several people that the valves and maybe the heads might be damaged. I am on a very tight budget and a single parent so PLEASE HELP!