Woohoo! I can't wait to see the finished product!!! 
I wish I knew how to use one of those tablets. I've been wanting to design a back piece tattoo and I've only ever used old school graphite n' paper (which blows since I'm a lefty).
Thank you
I'll keep you posted 
As far as tattoo designs are concerned, it depends on whether you want something geometrical or something organic. For geometric designs, you can just use a mouse in Adobe Illustrator. However, for something organic, Photoshop or Painter would be the way to go, with a tablet. for a beginner, I would highly recommend a Wacom Bamboo. It has 512 pressure levels, which is more than enough to begin with, and it is reasonably priced.
Learning to use a tablet is not difficult
If you know how to draw by hand, you'll know how to draw with a tablet
It is a bit counter-intuitive to begin with, since your hand is not moving on the surface of the drawing. But, I got used to it very quickly, and I am sure you wouldn't have a problem adjusting either.
For a professional, Wacom Cintiq would be the way to go, which is basically a pressure sensitive monitor. It is awesome, and extremely expensive. It also requires quite a bit of space to install. And, as soon as I will move to a bigger place, I am getting one, even if I will have to starve for a year 