Quote from rpbetancourt:
Before beginning, I found some small plastic bags and labeled each of the with the location the screws would come from once removed and the appropriate step number. Once the screws were removed I placed them in the labeled bags and did not have to worry about mixing screws up. Also, provided a good way to insure that no steps were skipped in the reverse process
I Generally just use a piece of paper with a rough sketch of the system and locations of the screws with prestik.