If your going to recommend a article, make sure you read it first.
quote from eb_sculpt "you'll have to put the time in. Draw stand by strand."
quote from the article
A lot of people start painting hair by painting the strands. Some won't even block it in, initially, but start frantically sketching in strand after strand on top of each other."
I'll also mention for future reference that hair like other things has two different properties diffuse and specular. The diffuse lighting is lower contrast and softer and its the diffuse light that will show the hair mass and the local color and the specular high lights help indicate the location of the light source, the curve of the hair, and how shiny it is. because specular are high contrast it makes them a good opportunity to show texture and details of the form your trying to describe. details are also present alot in core shadows but that dosent apply to hair a whole lot.