You can use nForce AGP if and only if (at least for the moment...) you use an nVidia video card, and you use nVidia's internal AGP driver. There is no AGP driver for that board that isn't a part of the nVidia driver.
This translates into "you need an Option "NvAgp" "1" in your XF86Config(-4 if it exists) file for AGP to work with that motherboard. But AFAIK, it works OK once you do that.
If you want to know about the sound / LAN / whatever, I have no idea. I think either OSS or Alsa has a sound driver for that board, but I don't know for sure -- in any case, the nVidia nForce driver (which has sound + LAN) is probably better anyway.