Lately I've been working on a dragon model. Since I am still total NOOB, I really like how's it going, but i've got few problems. As you can see from screenshots belowe, when I make a model, and it's not smoothed, everything is OK. But when I smoothed it (polygons->smooth), there are strange shadows there. Since I'm a noob, I really don't know what could be wrong. So I would really apriciate any help with it.
And, of couse, any comments are welcomed!

Belowe you have some screenshots.
Cheers