Hi there -
I too am just getting started. I had some old lures that needed repainting, so I said what the heck. I didn't want to invest much money.
I picked up an el cheapo airbrush at Harbor Freight for $10. Single action, but actually paints pretty well. Cant do fine lines without stencils, but it puts on nice base coats, fades and speckles (when desired) well.
I use a CO2 tank (I'm a homebrewer too) as my air source.
Walmart for paints (44 cents/tube of acrylic) and Devcon 2Ton epoxy ($2).
I dilute my paints with water, airbrush them on the lure, stick on some eyes and apply Devcon with a plastic fork. My first few have come out ok by my standards. I'll post some pictures soon...
I didn't want to invest much money at first, but I am off and runnning for less than $20. My airbrush may not last a long time or be remotely close to the best, but it works...
Having an air source may be the biggest investment.
Also, I just paint outside or in my garage, I put some newspaper behind the area I'm painting in.
Now, I just need to improve a little.