3d Modeling realistic Hair with polygons

Is anyone willing to share a good way to model hair with polygons?
I mean realistic hair.
At the moment I have a huge problem, all my character 3d models a bald.
And the results of my attempts at modeling 3d hair is not something I am proud of.

Any tips or detailed tutorials are welcome.

I would not suggest modeling hair. I would suggest using alphas and putting hair textures on faces though it depends on the character and what you are trying to achieve.

Its better to use a some plugins to get a realistic hair

I would recommend using a particle system. Not sure what software you use, but in Blender you can create really nice hair using a particle system.
You can even comb it

http://forums.cgsociety.org/showthread.php?t=776518 maybe this would help