nice bike to start with for a tear down. i've done like dozens of tear downs in my times, and the two biggest things are keeping track of all the parts and little pieces and remembering how things are put together. id do the plastic baggies with lables, or in my shop, i got a bunch of old tupperware containers and cambros for the smaller parts and lined boxes for the larger ones. and lable stuff, take notes on how things were adjusted and where they go.
i take it that you are going to strip it down completly, so don't rush things and go at your own pace. i am about to do the same to my 1959 amf roadmaster cruiser this winter as well as giving it a fresh coat of paint. since the horn tank, fenders and rear rack are missing, i'm gonna do a semi-custom thing to it. when i am done, people will bow to it (hahaha). be ready to spend the time needed to clean everything right and putting things back together. and the feeling you get once your baby is put back together and your riding it down the road knowing YOU built this bike and if anything goes wrong down the road, you'll be that much more inclined to jump in and fix it.
i am the self proclaimed 3speed guru of norcal, do if you got any 3speed specific questions, don't hesitate to ask. especially if its a sa hub. they are actually not too hard to tear down and rebuild. good luck.