My edit:
Seems that you are not only new to pixel art, but also fairly new to just art, now I know what you want out of this piece, you want it to look
good but how does one achieve something that you can feel is pleasant? Studying, hard work and patience, this is what it will take. What do you need to study?
Well, not in pixel art, pixel art is just the tool you're using, like a pencil or a paintbrush, if you're not good with drawing or painting, you most likely won't be very good at pixel art, since your skill transfers from traditional to what we're seeing now.
The main problems with this piece are as followed: Anatomy, light source, perspective, I could go on, I know, you don't want me to hear me throw at you more problems, but throw at you some solutions.
My solutions are (A good site to find most of these books:
http://www.scribd.com/):
Andrew Loomis - Fun With A Pencil (Basics of art)
Bridgman (Basics of anatomy)
Color Theory (There's plenty of this online, you just need to understand the basics, it will help you with lighting up your subject, i.e. 'shading')
Norling - Perspective Made Easy (Self-explanatory, though, if you need it explained, helps with perspective)
That was for just in general art, for pixel art, here you are:
http://www.spriteart.com/tutorials/http://www.derekyu.com/?page_id=218http://www.petesqbsite.com/sections/tutorials/tuts/tsugumo/default.htmI hope I have helped, even if its just a little, good luck with your piece, I'll probably try and help later.
Oh, uh, one more thing, since you're going to make a top-down RPG, it would be wise if you studied up on some game's graphics, i.e. Final Fantasy series, Chrono Trigger.