What type of AC coolant does a 1992 Toyota Camry take and Where is the low pressure port located to recharge?

It takes the old stuff. However you can put the new kind of AC coolant into it if you want. Walmart sells a kit for about 30 bucks that includes some refridgerant. Off the top of my head I think the new stuff is R134a. Regardless, it's the only kind you can buy off the shelf.

A mechanics shop will tell you that you need to replace some of the gaskets. While this is technically true, your car is a 1992 and you don't want to spend big money to do the crossover. It is cheaper to have a gasket that leaks a little and you have to add more refridgerant a couple times a year. The stuff that says it's for high milage helps a lot.

As far as I recall, the low pressure port is up kind of close to the firewall on the passenger side near the top. Mine is a '92 XLE. I have no idea if it's different for the other types. Without checking on my car, I don't remember for sure.

When you are doing the cross over, don't worry if a little bit of the old refridgerant hisses out. Just stand back and wait until it stops hissing. The only thing wrong with the old refridgerant is that it has chloroflourocarbons which is the stuff that supposedly kills the ozone layer. Just remember that one normal sized NATURAL volcanic eruption puts out more chloroflourocarbons than all of man kind in all the history of the earth.