Sven welcome to the cafe. In time you'll see that the only shooting we do is thru our Nikkors, so no worries, no flaming and no bashing here ;-)
These are wonderful model shots, a bit saturated but you know best. Keep them coming (especially your auto action series...) 8)
From the look of the picture, it seems like you used 2 lights or 1 light and a refelector. Try reducing the light from one side, adding a hint of shadow for me is well suited for male models. Plus the shadows adds some depth to the face.
Though for a first time, its pretty d@mn good, how I wish my first was at least half as good.
Great work Sven. Your model has great character, and your compositions are solid. I'll agree with Woody, it's time to hit photoshop and take care of that skin, plus you can add some subtle affects like a vignette to help push your subject toward the viewer even more.