Tony,
I started painting three years ago. I started with rattle cans, and found this forum when I was trying to figure out what was making my paint bubble.
I had already made lures that caught fish, but I wanted a better, more durable and colorful system.
Here's what I learned.
Painting is like throwing a baitcaster. Nothing takes the place of practice. And anyone can do it, since I can.
And you'll probably learn more from you own mistakes than from our advice initially.
If you are serious about painting, invest in a decent gravity fed airbrush, compressor, regulator, and water separator. You can find sources for all those things here on the forum.
Buy some airbrush paints, and start.
If you're repainting plastic cranks, sealing and priming won't be an issue.
If you're repainting wood cranks, do a search here for wood sealers, primers, and paints.
After you've tried some things yourself, you'll have a much better idea what everyone here is talking about, and your questions will be easier for us to answer.