Hey Light, I've written a fair few pieces for multiple instruments none of which are guitar. I can sight read music from learning the piano years back but the way I actually 'write' is in midi - it's so much easier. Eg open up Cubase or Reaper etc and click on a midi part, you will see a keyboard on the left side of the screen. From there, all you have to do is set the quantize parameters to the smallest note length - eg 16's and the time signature. You can then drop in the notes into the grid very easily and they sound out as you do so, stretch the note to the desired length, semi-quaver, triplet whatever. If you want to switch to standard notation you can do so by switching the view menu and you will get sheet music, which you can also edit easily. I still compose on the guitar but when inputting things into midi by ear you can get some refreshing new ideas because of the different medium. Makes things very handy!