Audacity is the basic recording program that I use on a daily basis. These are the things I love about it:
1. It's free
2. It's fast (you open the program and hit record, as opposed to setting up a Pro-Tools-like session in GarageBand)
3. You can compress and normalize any selected area
4. You can bounce (turn a portion of the recording into a stand-alone mp3 or wav file to import into iTunes) any area
There are plenty of recording programs out there, but in my experience nothing has been as easy and helpful as Audacity.
Download it here for free.
Keep writing (and recording),