Definitely a complex subject and process with a zillion factors contributing. I sure think we've been through this subject before on here but.....
Get all the research material together you can, the more the better; you can never really have enough and someone in the club should probably be a point man. A booklet like Gulph Mills's that was strictly a design evolution report from the very beginning of the club to date helps in a number of ways.
You should produce hundreds of copies and get it out to the entire membership as it informs them of what the course is, what it was, how it changed, when, by whom, sometimes the whys of the changes!
Historic aerials are extremely important and should go into the booklet--members grasp the changes in aerials very quickly, much quicker than even the best organized and best written text. The majority of members apparently look at the pictures and often with great interest instead of the text!
If you have as many architects come through over the years as we had it gets a bit more complex but somehow we really lucked out as the aerials and their dates matched the dates of the architectural changes really well and I also had all the necessary committee and board minutes from the beginning to date. With all this material you can accurately reconstruct the entire evolution of your golf course.
With this you can see the changes from one architect to the other and I can't tell you how much that helps when you present the booklet to the restoration architect you select. This kind of thing takes a lot of the guess work out for him as to who did what and helps so much in his evaluation of the course. Thrown in there are generally changes done by the club or a committee on their own.
This kind of booklet stimulates understanding of the golf course, what change did to it etc; an architectural evolution booklet builds pride amongst the membership in the golf course and the architect too, particularly if he's well known.
Then you form a committee for the entire process of putting a restoration plan together and taking it forward through the membership. I guess the Green Committee can be used for this if it's a good one.
Putting the committee together that is going to do this is a very important step and just selecting the members properly will be telling for years to come. Well after something like a booklet and just before selecting the committee you are about 5% of the way home and I have to go to bed now.