Kevin, if you look around, you will find a lot of threads on this. Now, before you go recharging your A/C, it is very possible that your problem isn't the A/C system at all. I ask you this question: does the A/C get warm when you start to get into traffic that is moving under 30 mph? If yes, then it isn't your A/C system at all. Odds are, it is your engine cooling fans not working correctly, which normally means your fan controller is dead. To prove this, let me know. The check is easy to do and requires no tools/equipment.

If you notice that your driver's side center dash vent is blowing warm/hot air while your passenger side center vent is blowing cooler air, then that is a blend door issue. If this is the case, let me know.

If you are truely low on refrigerant, then you have another issue that needs to be resolved before adding more freon. If you are loosing freon, you have a leak in the system and adding more freon is only delaying the inevitable. You need to take the car in to an A/C shop and have them do a pressure or vacuum test on the system to find the leak and then repair the bad component. From there, they will be able to recharge the system for you for a few dollars more.

As for the type of freon, your car uses R-134a with an oil added in. This is key that you get freon with the oil. No oil in the freon when you add it (unless you add it separately) will result in your compressor not getting proper lubrication and lead to sudden compressor failure. As for where you add it in, if you found the one port next to the firewall, then a more detailed look will show that there are 2 ports back there. One big one, one small one. The freon fill rig will only fit on to one of the ports (low pressure port). This is the one you need to use to fill the system. Just make sure that when you fill the system, you have the engine running and the A/C system on full blast (prior to adding any freon) and you only fill it to the recommended pressure. Not following this can lead to catastrophic failure of the A/C system.

 

Thermo to the rescu again...nice post specially for a newbie with no intro?
C'mon Kev, get a post into the new members section with a little info bout you / your car / location / history etc....Its forum etiquette
Hope you get your issues resolved