I've just figured out that it is very hard to master. Indeed, it's such a great tool for both photographers and illustrators that it has many features unused. Even if I've been using Photoshop a lot for enhancing photos and also to make digital artworks (photomanipulations and paintings), I know Photoshop is still hiding a lot of things.
This way, I've been going into searching tutorials around the web to look at others' techniques. I think tutorials are really interesting, not to "steal" or even make the same artwork, but more to integrate the technique and mix it with your own experience. Then you can achieve great effects.
All that to say that I'll be posting some links to tutorials I find interesting for everyone. I hope you'll like them as I do.