Ford Farm Boy,
What kind of results are you after? Some people don't think twice about brush painting their tractors, and others (myself included) want a mirrior finish on the sheetmetal.
If you are serious about learning to do body and paint work, then you need to invest in some good equipment. First of all, if you are after truely good results, you will need to buy quality paint. Quality paint is too expensive to waste making mistakes with junk equipment. You can take my advice now and save money in the long run, or learn the hard way.
1. You will need a good compressor (atleast 10CFM bare minimum) with a properly designed water trap and filter. The #1 mistake is putting the water trap too close to the compressor. The air needs to cool and allow the moisture to condense before it hits the water trap. Do some research on this topic.
2. You need a decent gun. The Devilbiss would be fine. Those cheap guns work ok for tractors, but the fan is small and they waste a lot of paint. Try doing a hood or roof on a vehicle, and you will find out really fast why you need a decent gun (uneven paint application will result in stripes). Not to mention, the small fan slows down the whole process, so it is even harder to keep a wet edge.
3. There are a lot of sub-standard paint products on the market. Do your research and use good paint. What ever you do, do not take a paint store's word for it. I use mostly Southern Polyurethanes products. Look them up at southernpolyurethanes.com. The user forum is THE PLACE TO GO if you are serious about painting. I gurantee you, the guys on that forum will get you pointed in the right direction.