Great, but it could do with some cropping, that way well... you get rid of all those things that are not part of the image.

Also this one indeed needs some cleaning from those pencil traces, and finger prints or dust, that can be easily solved if you change the levels of grays in the image.
You can do that with a free program like Gimp if acquiring Photoshop becomes too troublesome, i also think that NG on the Wiki page has some program recommendations that you can download and use for free: http://www.newgrounds.com/wiki/creator-resources/art-resources

They even have links to tutorials, but my lazy self hasn't read them so i don't know how good they can be, however the forum can give some great guidance on a wide variety of topics.