Firstly, the second sprite doesn't like this background color. The outline on the first brings it out, but some of the colors in your palette are so close in value to the bg of your post that the second sprite is very indistinct. The first doesn't suffer from this because it has an outline.
First sprite:
-Forms look good; I can tell what's what. As you've mentioned, the hands are blocks. I can't really help you there, as I'm not that good at hands either. The tunic might want some more shading to define its cylindrical nature; it's rather flat at the moment. You might want to replace the grey internal outlines you have at the moment with the skin shade tone. As it is, it's just an outline, but if it was skintone it would be a shadow due to the edge of the cloth. The dark lines on the arms seem random and un-necessary; I'm not sure what they're supposed to be. You probably want a shadow from the head on the neck, since everything else points to an overhead lightsource.
Second Sprite:
The arms are way too long. The way its shaded right now, his right arm would reach below the floor and his left arm would reach his ankle. Again you've got block hands, which someone else can help with. His right foot looks too wide, and his left foot looks to short. He looks much more muscular in this one than in the first sprite, largely due to the very defined pectoral muscles.
Overall, this is quite a good start. You've got some things to tweak, but the sprites are started well. Welcome to the world of posting on Pixelation!
Adarias posted while I was typing and provided an edit. Pay attention to it! I think, however, that the use of skintone for highlihgts on the tunic makes it looks like it has holes in it. Other than that, it's a very nice edit.