I think I can help you with some pointers, Arctic. Oh, and welcome! Pixel art is very enjoyable, I'm sure that if you dedicate enough time you'll find it quite rewarding.
1)
Start small: Don't make a 640 x 480 line art for your first pixel art, it's going to make it difficult for you to color and add detail. You can stick to a smaller size at first to get the hang of it. Then you can experiment with bigger stuff.
2)
Use a solid, clean line art: I don't remember who, but someone said here in this board that a broken line art would make a great coloring job not good. The line art is the foundation of the piece, so make sure it's clean and tweaked before attempting to color & detail it. There are other methods to make pixel art pieces, like sculpting the image from color blocks or defining a silhouette first with pure black or other dark color and then adding highlights, but the line art is the basic, most used method for sprites. Find something that suits your style. If you're not sure about the lines you got, you can always upload them and post here for comments and suggestions.
3)
Try doing tuts or coloring others' line arts: There's a great bunch of tutorials linked
http://www.wayofthepixel.net/pixelation/index.php?topic=222.0 (also a whole load of tools and interesting links, check 'em out if you haven't) and you can always take a look at the line art thread
http://www.wayofthepixel.net/pixelation/index.php?topic=499.0 where you can see lots of great examples of clean, good line art and you can even feel free to try coloring one of those!
I hope these small tips offer you the help you're looking for Arctic. Good luck!
Keops
