I've come to believe there are two types of talent, the blow-people's-doors-off kind, and the foundational, solid, persistent kind. Its not that one can't have a touch of the other or one is more hard working, its just a general distinction.
Professionalism is fairly simple: Be respectful. Don't bother people (in an obnoxious, unwarranted way, that is). Know your boundaries.
Networking is the part I never mastered, or, admittedly, wanted to master. Social networking never was my thing either and I'm still adverse to Facebook, though 6000 tweets later I've obviously caved to twitter. Grr. But when its used properly, in conjunction with your talent, and, more importantly your professionalism, it can catapult you into another stratosphere of possibilities for your work. So use it! Facebook, twitter, linkedin, myspace, comicspace, deviantart, forums, message boards. Get your stuff out there. If you've got the chops, someone will see it.
These are, by the by, my own personal gleanings only. Not to taken as gospel, just like most other things that come out of my mouth. Still, its not all rubbish.