I haven't really tried painting fondant yet, but maybe wanted to give a shot in the near future.

What all would I need besides the brushes. Brand that is popular? (better)

I actually buy artist type bruses as well as inexpensive ones at Wal-Mart.
Here is a photo of something I posted today. I also use lemon extract or vodka and any color gel.

http://cakecentral.com/gallery/2152295

I have used thinned royal icing or Wilton gel color mixed with water. For brushes I bought a big value bag and sterilized them. I only use them for foods.

So far I have only painted text onto fondant plaques because I hate to use a bag for text but I'd love to try a picture. In my gallery you can see a gift tag I painted on with Wilton and water and the white and red Olivia cake I used diluted black royal icing to paint the name.

I painted leopard spots on buttercream...and I used gel colors and lemon extract. It's like working with watercolors....very fast drying water colors! ;D

I bought artist brushes and use them only for cakes. I use gel colors (or Americolor) and vodka. HAVE FUN. I really enjoy painting on cakes.

And FYI, Wilton now makes a GOOD set of brushes (not the rinky-dink set of three lavender brushes that they originally sold), all green, different thicknesses, with different points to them, very easy to work with. I LOVE painting on cakes and have a full set of brushes that I exclusively use for food, but I feel that much better knowing that my brushes were food safe from the get go .

Other suggestions (i.e. apart from the ones mentioned above which I also use) are luster or petal dusts mixed with vegetable oil, or gel colors mixed with water.

Bear in mind that gel colors are generally meant to color white paste, so the direct color will look darker. You can modify the color by mixing with a white gel color before painting.

I use Americolor gel colors

Hmm.. I tried vodka and americolor this weekend.

Is there a technique to making a certain color, or do you just have to already be mixing with that specific color.

When trying to make lime green, I failed pretty hard. I figured it works like fondant, but this did not at all. Maybe my portions are way off though. Maybe I should google first on mixing gel colors.

Is luster dust easier to work with, or the same.

I love painting with airbrush colors. They are already thinned down and they dry nicely.

I've also mixed gel colors with ever clear.