First stab at digital art

Just keep drawing with the tablet. You will get over that strange feeling of not looking at your pen while you draw. It's the dissonance between your computer screen and the tablet that makes it difficult.

 

tool needs to work as if an extension of the hand..doodle a lot...play...this is a doodle from my old days (games, 3dsmax, opengl, dx and web sites/flash tinkering)
this was pure photoshop doodling...but I had been doing photoshop stuff for about a year.

 

Try these:
 
 #1- instead of a white background, use a darker value, then make a new layer and draw over it.  using a mid-tone cuts corners (in a good way)  try it with a medium gray, then draw over it, then under the lineart layer, use a darker gray for shadows, then use a lighter grey for light and white for highlights.   You can make a very good looking piece of art with only 4-5 shades of gray
 
 #2- Setting a layer to "Multiply" renders it transparent, but keeping it the same in appearance.  It will enable you to add color to your artwork.  Try taking this piece you made, setting it to "multiply", then add a simple color underneath it,  then use a lighter color for highlights.  
 
 #3-  Shadows--  there are two kinds of shadows, a light shadow, and a cast-shadow.  Research these, they arent too difficult.  I'll add some little tricks i know later, you'll love 'em.
 
 And here's a neat little tip for a cool effect on artwork-  Copy some lineart you drew, then select all, and copy, then paste.
 
  Drag the pasted copied layer underneath the original, set the original to "multiply", then on the copied layer beneath, use the circular blur filter, and drag it as needed.  You'll notice a neat little effect that makes drawings look extremely elegant.  and the best part of all, is it only takes two clicks and a drag

 

No problem, man.  Here's a couple of good books that'll help you draw better:
 
 Figure drawing for all it's worth, by andrew loomis
 
 Drawing the head and hands, again by andrew loomis.
 
  Both are full of great techniques, but the real goldmine is the writing in both.