First a definition:

A digital audio workstation (DAW) is an electronic system designed solely or primarily for recording, editing and playing back digital audio. DAWs were originally tape-less, microprocessor-based systems such as the Synclavier. Modern DAWs are software running on computers with audio interface hardware.

Secondly, some items from Adam Dachis on LifeHacker.com:

 

 

From DSC:
For those who want to dip their feet into the pool quickly to see what it’s like, I would recommend checking out Garageband — it’s a powerful tool that can give you some nice results — and the learning curve is far better/easier than the more complex tools out there.