Forum:Help a video noob out.

So with MW3 coming out and playing COD regularly since COD3 I've always wanted to record and edit gameplay with mic audio. I have absolutely no idea where to start. I'm running a Macbook Pro with 32LD400 LG tv. I would like to keep the total cost of the hardware(s) under $500. Any suggestions would be great.

Also, I've always been THAT GUY who plays stupid soundbites through his mic, is there any way to make that audio quality better?