Just make sure the file size is under 150k. As long as the filesize is under 150k then you can post it. If it's bigger than 599 x 700 it will be automatically resized :D!
I think perhaps you should sharpen your pencil. The outlines are looking a bit murky, when you shade try and shade with the object. If it's a round object try and make your shading curved and things like that. The big hole in his chest doesn't look right, I'm pretty sure there would be something there and it would be darker. Keep practicing :)