So I'm thinking about adding A/C to my car while it's down. Is there any hints or tips that I'll need to know about this? Like how to drain the freon (or whatever it uses to cool the air), and can I just hook it up to the heating ducts and it be good as new?

I know I'll have to add the HVAC controls, but Its supposed to come with my 4th gen Dash so I'm not worried about that.

I will take out as much as I can... so is there any wiring that I'll need? I know that when you turn the A/C on it is supposed to tell the fuel system to pour in more fuel in order to keep the RPMs up...

What safety precautions must I take when dealing with A/C lines?

Any help will be much appreciated!!