Headset/mic jacks, soundcard, and USb adapter?

[Knocc Out]

Hello, right now I'm using a Audigy 2 sound card, my speakers connect to it using 1 orange jack going into the digital out port (I think) of the sound card (even though im using analog setting it still works :S), I will soon be buying a headset and am confused as to where I will plug it in, I want to use the headset and mic port at the front of my computer. and I have headset and mic ports on my sound card, but I am worried that as Im using a sound card it will not recognize if I plug it into the front of my PC, also I was wondering how the headsets that come with a USB adapter work, would I be able to get sound if I plug it into my USB at front of the pc?