A beta of the new version of audacity is available for download. I haven’t used this myself but it comes highly recomended to me by sound engineers. I asked a few of them what a good package to buy for recording and editing sound would be and they all said don’t pay any money use this instead, multiple track recording and editing and completely free. I guess this is the audio equivilantn of what gimp is to photoshop.
Check it out