I am planning to purchase a new iBook and will use this to compose music from my Korg N1 keyboard.  I would like any pointers to sites or forum threads that might give me some tips on exactly what I need, the issues I will be facing when I do this, etc.  

I have several songs that I composed on the N1 and dumped as MIDI files into a Roland PMA-5 and now I want to move these into my laptop and do some tweaking and arranging - then copyright - and submit to some sources I have that are interested in this music. I'm not sure what is the best and easiest to use software for this.

Thanks.