Paints-wise, I'd suggest a water-based acrylic; these can be thinned out using just a drop (or two or three) of water and generally clean up easily as well. Apple Barrel and FolkArt are cheap brands that can be found at general hobby shops (Hobby Lobby, etc.) and WalMarts. Higher-end brands---Vallejo, Model Masters, etc.---can be found at your local, hole-in-the-wall hobby shops.
When it comes to the veins (and the detail that will need to go into them), you may want to find something ither than a paint brush. Something with a straight tip, like the clay modeling tools at hobby shops, and very lightly brush the paint on in thin layers. patience is the key to this type of work, not just the paints and tools!
Hope this at least gets you started!
Good luck; I look forward to seeing what you come up with.
