I'm not skinny, but I'm not dead fat, what to do?

[rider_1]

OH my good lord. You want to gain weight and you don't eat carbs, ummmm, WTF. Forget about the exercises/gym, you want to grow? You need to friggin eat man. WOW. You need food to grow, if you don't get enough calories you'll never, ever pack on any real mass at all. First of all, if you're serious about gaining mass (i.e. bulking phase), you need to generally eat 4000+ calories/day. You absolutely need to ingest carbs.
As a general rule of thumb to maximize growth, you want to eat meals of either fat+protein or carbs+protein (this has to do with insulin response--one of many factors that trigger/enhance growth). Body builders, in addition to using large quantities of roids, also inject insulin at certain times to further enhance their growth. Anyways, off topic here.
Eat more and you will grow. And for God's sake, get some carbs in you man.

Here's a link that probably has all the answers you'll ever need: www.t-nation.com