Headset for Double Agent and more?

[Armbarsalot]

Hey everyone, new here
I normally play console games but am getting into PC gaming. I bought the Logitech Extreme PC Stereo Gaming Headset w/ microphone hoping to use it in the new splinter cell game.
How do I actually use the headset in games though? I bought the new splinter cell and would love to be able to use it in that game... also, I am used to xbox live where I can play any game with people on my friends list. Is there a service similar to that for the PC where I can have a friends list and meet up for games? Thanks in advance everyone!
Armbarsalot

[Chocu1a]

x-fire