Step 1: Paint
What I used for my golden Minifigure was model paint (acrylic paint). You can buy these paints at a craft store. Were I got this paint from was Michael's craft store. There you have many choices of paint and tools.
Step 2: Brushes
Like I said before, the brushes I recommend are acrylic brushes and you can also get those at Michael's.
Step 3: Painting You Minifig
I painted my Minifigure by putting claps on each individual piece, then when you're pieces are dry, you can attach them to each other. Drying takes 15 to 30 minutes. Your mini figure what really have much poseabillity, but it's still pretty cool. If you fiddle with it like I did the paint might rub off, but it does look amazing. Comment if you like this or you have made one.