There are some really great indies over on tigsource.com (art board). I've seen a lot of those guys pump out some really cool pixel art. I'm sure you'll find a fair amount of people willing to give you advice. You might check out gamedev.net as well. I know Mark Eugn does a LOT of epic pixel art (gd.net journal).
To showcase your work, http://carbonmade.com/ might be the way to go. You can break what you do down into categories so people can find their focus faster. The interface for the site is nice.