The original questions were "how difficult is it for someone who doesn't play guitar or any other instrument for that matter. Sure i can make chord progressions and i hear what i want in my head but is it going to be pretty easy for someone in my moccassins?"

Garageband and Logic were mentioned. What is the difference between these programs -- do they do the same thing?

I've had the BIAB demo and worked with it a little but wasn't able to spend time with it to learn it. Plus my musical skills are sore lacking and arthritis makes it worse. I've heard good music from BIAB but am still confused as to what it is actually supposed to do.

All I've ever done is just play into a mic for Audacity and in the old days a cassette recorder.