If you really want to be an artist and work on PC, you should take a graphics tablet. Drawing with the mouse on PC is really a pain even when you are a good artist. Wacom is well known for that and they have a tablet for beginners : the "Bamboo" model. Don't take a huge one. I took one and I only use a small portion of it.
Of course, as it has been said you can also draw on paper and scan the drawing to color it.
The best pixel art tutorial I found, is this one : http://makegames.tumblr.com/post/42648699708/pixel-art-tutorial
For pixel art there is also this website : http://www.pixeljoint.com/default.asp (go in the gallery and enjoy )
Here is my advises :
Try to build your drawing with basic forms like a line for the vertebral column and a oval for the head.
Something like this :
Found on http://www.foxprints.com/tracy/misc/tutorial/char_drawing.html
You can use his basic forms, they are very good and common.
It's important for anyone because if you constantly start with the details, you will realize that you will not be able to draw something with an original position/point of view.
Learn how to draw something with the perspective.
Learn anatomy and proportions.
Copy shamelessly your favorite artists BUT always start with the basic shapes (as mention above) or you will learn barely nothing.
And of course draw a lot.
When you are comfortable with these points (especially the anatomy) you must take a big book of Burne Hogarth.
This artist has an old style sometime, but it will give a real deep knowledge about anatomy and muscles (and how to draw them properly).