First find RestoRicks list of what to do and what order to do it in.
Second, figure out the parts you are going to need. Divide this into two lists, stuff that is being reproduced and stuff that you are going to have to find NOS or restorable OEM. These lists, unfortunately, will expand.
Third, keep the lists with you and go to car shows, flea markets, Carlisle, Mopars at the Strip, local clubs and look at prices, conditions and availability of the parts you need. You will quickly figure out what is avaialbe and what isn't.
Like the others have said, there is no such thing as too many pictures, too many drawings, too many bags, bins and Sharpies to mark everything.

i have a few 71's
my advice is save your money!!
71 rr is a one/2 year only car/parts with a strong following..
the cost of parts for these cars to roi is probably
the worst of all in the hobby

nice original parts are generally not cheap and do not stay for sale very long if they are reasonably priced.

nos is stupid expensive if you can even find it
i have stuff i've been after for many years
and i'm lucky to even see it come up for sale

MOST of the repop stuff available is carp or it has major issues
do some research before you buy ANY of it so you
know exactly what you are getting into