There are specific tablets for digital art if you are planning on connecting/drawing with a laptop. But If you aren't and just want to draw with a tablet there are many decent apps and all you would need is a basic touch screen stylus from a store. Although if you are planning on using a computer/laptop, I recommend any woccom tablet, which you can get a decent one for a decent price on amazon.
To sum it up-
if your planning on drawing with just a tablet all you would need is a touch screen stylis and a drawing app
If your planning on using a computer, go to amazon and search 'woccom drawing tablet' and that would give you what you'd need.