I bought an 1992 Toyota Camry 4 cyl with 126700 miles on it, runs excellent. The lady I bought the car from never had the timing belt changed, do I need to have this done and what do they charge? If say the belt breaks will there be any internal damage or is it what they call free spining?

 

Yes, it needs to have the timing belt changed, its like 60,000 miles overdue. Toyota says change it at 60k. So it shoulda been changed twice now.

You mean is it an "interference" engine and the answer is no. This means that if the timing belt breaks it probably will NOT wreck your valves (from the pistons hitting them). But even so, the timing belt can get loose enough to jump time, which will definitely affect performance and not in a good way. So i'd just change the belt.
I would also change the idler pulleys and the water pump too at the same time and then you can drive this car another 100,000

 

how much does that usually cost?? i would like to save some cash and do it myself but i am considering having Toyota do it so i can have some sort of warranty

 

the dealer will rape you to the tune of about 600 to 700 dollars if you can do the work yourself it will run you less than 150 to do the idler(tensioner pulley) and the water pump.

 

is it something i can do in a weekend? and do you know where i can get a guide to doing it?

 

Theres a good description of it in the chiltons manual. I dont know about doing it in a weekend. Its not all that east it depends how good you are with a wtrench