A list of tutorials for my friend, arranged by topic! She's new to Photoshop, and I am definitely not the person to teach about it....but I can refer to some good ones.

Lineart:
Lineart-Shading Anime Style by ~akuryouu
Lineart tips for anime artists by *getty

And, of course, if you're fine with your lineart the way it is, you don't even need to use the pen tool...on the bottom right side of the screen, where it shows you all your layers...there's a box with a drop-down arrow that says "normal." Change that to "multiply," and put all of your color layers under it.

General Coloring:
Soft Coloring - Deji's way XP by =dejichan
Tutorial for soft cell shading by *getty

Hair:
Drawing anime hair by ~TheEclipse
Coloring Hair - Deji's Way by =dejichan - The pen tool reeeally helps with this since she uses a tablet in the tutorial...
Coloring Hair in Photoshop by *mree
How to paint anime-styled hair by *getty

Eyes:
Coloring Eyes in Photoshop by *mree
How to Color Eyes by *raila - Designed for markers but I could see its working in photoshop, too....
Drawing and coloring eyes by =dejichan
Eyes Tutorial +anime style+ by =raykit
Tutorial for how to paint eyes by *getty

Yup. I'll try to get more soon, especially on general coloring...And maybe I'll make a skin one, since there aren't a lot of detailed ones out there covering that. Maybe a clothing one, too, since my techniques for those are the same.