I'm doing the brakes on my 05 GT, what is the minimum rotor thickness? Also, what are your opinions on turning the rotors, is it necessary with new pads?

Thanks in advance.

Also, where can I get a good shop manual for this car?

 

1) I have not looked at these rotors yet, but all I have seen have that information cast in the body, usually on the back side.
2) If the rotor is heavily grooved, they should be turned. If relatively smooth then leave them alone. If they are needing to be turned, then tell them you want a absolute minimum cut. Some operators will take a unnecessarily heavy cut to make it easy for them. You want to leave as much material on the rotor as you can. That way in the future you may have a chance for an additional cut or two.
3) Ford?