group picture

this took longer than I expected to color. I think I'm getting better at photoshopping... kinda... but I just saw [link] done by sketchboy, and my confidence went "screech crash!!"... Will I EVER get that good? so anyway, I took advice from people around me, and I colored everything in layers... I still don't really get the importance of this, but I did it anyway. Any further coaching, hints tips, tricks and such would be greatly appreciated. Thank you. ^_^