Good resources for improving at Insurgency?

After playing the Sandstorm beta, I've felt something I haven't felt in an FPS game for a long time, not since I played Call of Duty 4 way back in the day - that burning desire to overcome my newbieness and get better.

Are there any good resources out there I can use to improve my Insurgency game (Like good beginner's videos, competitive players, etc.)? I realize the next beta isn't for two more weeks, but I'd like to start figuring out what I need to focus on and improve before then.

I highly recommend playing Insurgency and getting a feel for that game since many of the mechanics and tactics are similar and directly apply to Sandstorm.