Hey DK.
I read this site by Derek Yu:
http://www.derekyu.com/?page_id=218
As well as loads of other online tutorials. Here's some more I found useful:
http://www.qubicle-constructor.com/wordpress/tutorials/
Specifically:
http://www.qubicle-constructor.com/word ... art-basics
(Qubicle Constructor was used by its creator to do the slow-mo 3D voxel bar scene by the way. Have taken link down, but full video should be up in around a week and a bit).
In short - get a 1 pixel pencil in Photoshop, zoom in really close to a small document (I worked @ 200 x 113 pixels, scales up to HD 16:9 pretty well) and then go for it. It REALLY helps to have a good idea of a rough or something as its easy to get lost in that small detail. I used a Cintiq to draw stuff, sometimes rough at first, and then as I read somewhere else, pixel work is more like sculpting than drawing in many ways. It is TEDIOUS ay ay ay but if you just try drawing something without a plan...well, I guess it can work. It helps to figure out how much detail you'd need. Say you need to see the pupils of a character, maybe draw that first otherwise down the line you'll figure out that WHOOPS you don't have enough pixel to put in a pupil without making the whole eye black, etc...
Also when scaling up or down in Photoshop its essential to use the NEAREST NEIGHBOR interpolation, not the default BILINEAR. And you gotta scale up and down in exact multiples of the image size. So if I have a sprite 15 x 20 pixels, I'd scale up 2 or 3 or 4 or 5 ... times. Not 1.5 or anything else I'd end up with the computer trying to figure out where to put 'half' a pixel. So, 30 x 40, or 45 x 60, or 150 x 200, etc...
Was an interesting exercise in minimalism, I may have even gone SMALLER than 200 x 113 pixels, something I want to try for another project, like 20 x 13 pixels and see if its still possible to get something interesting out of that. Surely it is.
Then I upscaled to 1600 x 113 for Anime Studio as the pixels don't look too good when rendered in AS.