im new to painting, but am looking to get started. I have been
looking at a few air compressors, but i really dont know what i am
suppose to be looking for in terms of; cfm, psi, tank size, or
horsepower. i found one with 4.4cfm@90 psi - 11.1cfm@40 psi- 125psi
max - 21 gallon tank - 4.5 hp. Is this going to be adequet for auto
painting, please help!

I'm trying to remember from my auto painting days. My shop had a 10
cfm@100 PSI, 10 hp, 100 gal tank. I used high pressure spray guns to do
basecoat/clearcoat jobs. The compressor could just keep up to me. If
anyone else was using air for sanding, I could drain the tank before I
had one coat on. I would have to let the compressor catch up between coats.

Are you hobby or commercial painting? If it's for your hobby, you can
let the compressor catch once in a while. If you are making your living
off the output of your paintbooth, you would best be advised to get
engineering help from DeVilbiss or one of the other big paint companies.

You have other issues here too, like clean and dry air as well.

BB