Don't wait to get started. Doesn't cost much to start taking one apart to find out what it needs.
Do that and keep a list. Find out by asking which parts are the hardest to find,and make a special effort to find them first. This has several advantages,the prime one being are that any rare part you buy today will be cheaper now than it will be in 5 years,AND you won't have to stop your restoration 5 years from now while trying to find that rare part.
Plus,it keeps you "in the game" and makes sure you don't lose interest.
I haven't turned the first wrench on my basket case 33 Plymouth coupe yet,but already have every part I think I am going to need tagged and put away in my shop. This includes the 6 carb 330 DeSoto hemi,and a push-button 727 with the controls and cables.
The only parts I can think of at the moment that I don't already have are the paint,upholstery,and the glasses.
Hope to sell my stock "older restoration" 31 Plymouth coupe and my 37 Dodge truck this spring to get the money and the room in the shop to start working on the 33. It's going to be a "50's street hot rod" with stock body including fenders,but I MIGHT leave the hood off. Even if I do,it will be restored and stored inside my shop so the next owner can use it if he wants.