is there a "notes" section in GB? i'd like to write some notes for each song (chords, arrangements, etc.), but i don't see any way to do this...
There's a "piano roll" style MIDI note input panel; not sure exactly how to get to it but it's definitely there--try double-clicking a track? Piano roll is the standard way of doing notation in most music apps, aside from direct "staff" style, which is only really in higher end stuff like Logic/Cubase. Ableton Live uses "roll" exclusively, among others...
You could buy a $ 15 licence from myriad-online.com for melody assistant, write your ideas and import them via garageband import - in combination with software instrument options in gb - food for years... ah, grab some audio units too...