Anything that comes from reliable sources. I'd be pised if I was reading something written by some kind of half-wit that barely knows what he's talking about. It might be blunt but that's just how I am, if you can't confirm.... don't write it.
As far as the actual content I say keep it simple like mosto ther magazines already have. This would mean reviews about guns, gear and parts, game reports, new player tips for gear setup and similar thing.