I am working on a high-poly head currently (500 Faces), but i don't know how to create a good looking hair...
so perhaps you have any ideas or know a model-download as example???

Thx kasimir

here is a pic of the head:

well 500 for a head is considered low (or maybe not-too-high) nowadays.

I suggest using textures with alpha channels. You may use 3 or 4 hair-layers with that alpha enabled textures, and it will look good.

as quad said, alpha layers, over top, but you might also want to paint some hair directly to the top of the head as well so that any areas you can accidently see thru wont look bad.