See the final result of this work HERE!!! It's very different, 9 more hours have been involved on it to finish it : [link]
I've been asked lots of times to do some tuts.... here's one of them, I'll do more when I have time
It's not very realistic since the image has been painted very quickly (about 45 minutes) but it explains how to paint realistic hair if you take the time to add details as explained on the tut
I hope that it can help
------------------- PLEASE READ!!!!!!!!!!!!!!!!!! -------------------
I've written "burn tool" instead of "dodge tool"
. The dodge tool is not necessary (I barely use it, I prefer avoiding to use it and paint the lighting manually usually) but it's a good way to obtain nice results very quickly and easily.
If you don't have the brushes already installed, you can add them by choosing them in photoshop library
If you want to obtain realistic hair, 2 or 3 hours of work are necessary (I usually spend 3 hours on the hair, I've only spent 25mn for the tut and 20mn on the face so it doesn't show how far you can go using this method)