I can't afford a new fridge right now, and I probably won't be able to for a while. But the fact that the freezer is still working gives me some hope that whatever went wrong is simple enough to fix on my own. Are there any repositories on the internet where I might find a guide or a checklist on diagnosing the problem?
EDIT: Thanks so much for all of the help. Unplugging the it and letting it defrost for a couple of hours actually did the trick. It's now getting cool again.
Move it out enough to see the back. Older ones will often have the schematic glued to the back or in a pouch and if your lucky there might be a ladder logic diagram or brief explanation of operating flow chart. Either one makes trouble shooting a lot easier. Also searching the brand/part #/model on one of the appliance part sites usually gives and exploded view and will tell you if there is separate compressor units and fans( high end), one compressor and two fans or just one compressor and fan like the top freezer models. Decent fridge thermometer helps I got a good one specifically for fridge/freezer made by Taylor . Proper fridge temp is supposed to be about 40F.