Skin Questions

I am sure some of this might have already been asked and/or brought up in another topic, but I guess i'll do it anyways since i have the right to be lazy.

I have just learned how to use PhotoShop and it's working great, I have yet to finish my first skin (Which is looking good to me so far) but I have a few questions. I am using PhotoShop 7.0. When I use the laso is it auto-matically suppose to target a section of the body? i've been using the Ploygonal Lasso so i've kinda had to shape which parts i wanted to edit, but somewere i remember seeing that if you go over the black parts of the skin then it will screw up. How are you suppose to know which parts are the borderlines of the actual skin? I couldn't get the lasso tot arget idivindual body parts... so i've kinda been guessing... any thoughts anyone?

EDIT: Moved to the skin section by BlacKDicK.

We must guess the wrapping using blizzard skin as base. I didn't understand your question well, but just select normal lasso tool and hold the mouse selecting all the part you want to skin (I skip this and make all without lasso, just using on some special cases, where i select some part to duplicate a layer or add some kind of effect).