what sketchling said was he thought details on what you need are on our page one but we dont. The link he posted was details on a larger screened version of the DS ;)
So here's what ya need buddy:
A Nintendo DS Lite (not a bundle) then a card adapter, perhaps an R4 or M3 with a SD Micro card:
details found here
the you'll need to download Homebrew Colors which is
found here
Then you just need to kick back and paint, providing of course the company you order from has stock of the cards unlike mine



