A deicent digital camera.
I take pic's of EVERYTHING and various states of dissasembly.
These have saved my butt MANY times on HOW something is supposed to go back togather.
I create a folder titled 34 Chevy and just keep creating subfolders in it for whatever I'm working on and even subfolders in them.
Like Engine,Intake,Cam,Pistons,Bearings,Oil pump,ect. So I have a record of what was done and what it look's like.
I pulled the heater box apart on my 69 to rebuild it and it came time to install the diverter door inside of it and I could not rember which way it went. Looked up the pic from tearing it down and there it was.
each month,burn a copy of the 34 Chevy folder on a CD in case your PC wrecks. This will have ALL the subfolders included so there is no need to copy them all.