I'm entering this talent show and I'm going to do an acoustic version of a song. Except I know nothing about acoustic arrangement. Can anyone give me some pointers in this or pinpoint me to a lesson on GMC about acoustic guitar or arrangement. Thanks

Here are couple of my lessons that you may find useful mate:

http://www.guitarmasterclass.net/rhythm-gu...erry-christmas/
http://www.guitarmasterclass.net/misc-less...writing-lesson/

If you want to do everything on just one guitar, you have to have in mind the melody and the groove, then you start making substraction so everything is playable, may be if you post the song and the chords do you like on it we can help you better.