Attached Link: http://www.renderosity.com/mod/gallery/index.php?image_id=1832944&member

Good hair renders depend on a lot of factors, first of which is having a good model.  If the base doesn't lay correctly to begin with and have enough layers to look full enough no amount of textures or shaders will make it look real.

Next for me is the actual image maps used.  Do you need to use realistic photos? Not always, but they do tend to give the best results.  Take a close look at your own hair.  Tho you may be blond or brunette or a redhead, you will notice that there are actually many many shades in your hair, and that one strand is rarely the same color from root to tip.  For realistic colors, photos are just the easiest way to achieve this.  Transparency maps are very important as well, and really the only advice I can give on those is they take practice.  A lot of models come with very good transmaps to start with.

Shaders.  You can really make or break a hair with shaders.  And not every hair should take the same shader setting, again it's going to vary on the model.  I like to go for a low intensity specular setting set fairly large.  I usually start with a specular value and highlight size around .3 and adjust from there, that gives you the soft look.  i then use the alt specular node with some anistropic plugged in to get the shine.  A little bit of translucence and a good bump and you are on your way with the shaders.

Lastly, render settings.  It does no good to put all that work into shaders and textures if you arent going to show it off with a good render.   I know a lot of people like to turn shadows and raytracing off on hair to save render time, but you will nearly always turn out a very flat looking hair in comparison to leaving it on.  Also turning down your min shading rate will bring out more detail in the hair.  If I am looking to really show off a hair I will turn it all the way down to 0 most of the time.  I'm attaching a Screenshot of the render  settings i used on the linked render to give you an idea of what I use that seems to work well for me.