Yep audacity is the shit when you're looking for free software. And it doesn't have the 'damn-this-serial-doesn't work' problems..
(To record your mix, play your mix and put the drop down menu on stereo mixer. Then just hit record)
Put all software off that make sounds, ex. msn messenger, your anti virus (update reminder)...
cough cough ** Perfect way to steal mp3's from myspace, d&barena, ...