How simple? Pro Tools has some lower end versions that are able to do quite a bit. Do you want to just record 2 track things, or do you want multable tracks? You can probably find a Pro Tools demo, also check out Sound Forge for 2 track recording, it is pretty to use, and can allow you to do tweeking, affects and other things, many online shows do their whole program with it. Another decent program is Cake Walk Sonar.
You can ask any other questions if you want, unfortunatly I am a PC user, but there are alot of solid products that are for Mac and PC both.
Adieu