The Warded Man by Peter V. Brett
Paperback – Del Rey – Apr2010
As darkness falls each night, the corelings rise, demons who well up from the ground like a hellish steam, and when young Arlen decides to brave the night roads and face the demons, he attempts something not dreamt of since ancient times: a stand against the night.
Book 1 of The Demon Cycle. Also titled The Painted Man.