1) Audio card. I don't know, may be that computer is lucky enough to get good on board sound. But 3 of them I met in person, were simply horrible. If you spend about $100 you can buy M-Audio Audiophile 2496. You will have dramatically better audio quality. I'd even say that only from here you can call it "a quality". Btw, it has RCA inputs/outputs (and an S/PDIF).
You should invest some money in a decent audio card. Onboard sound is ok for playback of the system startsound and YouTube videos, but certainly not for recording. Something like the recommended Audiophile cards are ok. Make sure your Linux uses the ALSA sound system.
If you just need a simple way to record you can just use the "arecord" command which ships with the ALSA drivers. It can record in 32bit formats (if your audiocard supports this, why you should invest some money here) and can stop after a specified duration. It is currently limited to plain .wav files (thus 2GB max), but will split if reaching 2GB, so no audio will be lost. When you edit your recordings later on you can merge your audio files again.
-- ---> Dirk Jagdmann ^ doj / cubic ----> http://cubic.org/~doj -----> http://llg.cubic.org
