Before you read this i made a video here: http://www.youtube.com/watch?v=6yzOkjJfZQ8&feature=plcp
step 1 base
this is where you are going to be putting all the little details, the base is your head, arms,legs etc...
when making it be sure that it is not just Steve and remember you dont need any real detail just yet

step 2 clothing
be sure not to make it just a steve shirt or a normal t-shirt, make sure it is unique and has several pieces like a logo on the shirt or a fancy belt just be creative

step 3 the little things
just add some simple things like backpacks

step 4 SHADING!
to shade you must go over everything you did before! take the same color that you used and make it the next shade from it, if the shade is too different from the original color use a color wheel and move it just a little:

it can be darker or lighter depending how dark the original color is. do this with all of the pixels on the skin, putting the shades in different patterns to fit the skin, if you cant find a pattern to fit the skin just use the darkest shade of the original color and go from top to bottom making the colors on the top darker and on the bottom lighter

just like on the yellow line of this color wheel instead to it pixel by pixel.
when you are doing the head do all the colors on the edges of the head darker than the ones in the middle, just like if the sun was directly above you. this is a good pattern for the head
with arms and legs do the same thing
and with the body do whatever pattern fits the skin