more than likley its a 1/4" plug. youll have to go to radioshack and get a 1/4" to 1/8" adapter. i think they are like 4 bucks. that is what i sometimes use to record guitar.
Mine looks like a 3.5mm (1/8") plug. It's a wireless microphone that came along with the receiver. Right now, the receiver is connected to a mixer, which is connected to the TV
Well your pc will have two places for your 3.5mm lead. The first is the mic jack, which will accept raw un-amped signals, and amplify them to audible levels. The other is the line-in socket, which does no such alteration to the signal, and leaves it unamped. That means the signal has to be amplified using a preamp before it hits the computer.
Motherboard and soundcard based amps are usually of lousy quality, and you tend to get hiss and other problems, but not always. I personally record to my computer using a Shure SM57 mic, and I use an Audio Buddy preamp.
Plugging the mic receiver into the mic jack in your motherboard is the way to go to start with, just to get an idea of sound quality.
Well if you go the Audio Buddy route, the box has inputs for 1/4" jacks. If you just want to plug it straight into the back of the motherboard, all you'll need is one of these.
I do a lot of recording on my computer with Shure mics mainly SM57's--nice chose magicman-- and run them through a Mackie mixer out with RCA to 1/8" cord into mic or line in on the sound card. It works great a you can adjust the levels and EQ from the mixer before going to the computer.