To my knowledge there is no G-Body assembly manual like there is for so many other cars. I'm trying to get one started using the parts manual diagrams until I can get to the archives at GM for the real PAD documents. In the interim, here's my best recommendation:
Take lots of Photos. Digital photos are free until you print them, take more than you'll need and print the ones you end up needing. Take photos of every piece you take off the car, if it's complex, print the photo and write specific notes on the back of the page. Review the photos after you take them, make sure they’re not blurry or out of focus, if they are, they're probably worthless. Buy a big fat three ring binder and a punch for the photos you print so you can put the photos and other information in one central location. You can even buy some tabs if you wish to be really organized.
Bag the hardware by specific components. Get the good bags and don't just throw all the door hardware in a bag. Separate the window regulator bolts from the door panel screws and etc. Write a good description of the parts on the bag before you put the parts in it. This way you'll be able to read the description instead of having to cipher your chicken scratch. You could even fold up a printed photo in the bag along with the parts. Zip Lok bags are inexpensive and well worth the investment.
Have your local Chevy dealer print off the Component view (exploded view when talking F__d) of the area you're working on. Yes, I realize it's a Cutlass, but there isn't any Olds dealers left and all GM dealers use the same Electronic Parts Catalog (EPC). This view will show you general locations of parts. If they print off the nomenclature sheet, you'll know what the parts are called and if they're still available. You could buy a Parts Illustration Manual on eBay but they're getting pricey. I don't have any of the JPEG versions with me so I couldn't post an example for you.
Scan and or save everything you find on the internet or are provided in a digital file for your car. Make sure you back it up once a week and/or after you add files to one, you should always make sure both files are the same.
Buy a cheap parts car if you have the room and the resources. Don't take it apart until you need something off of it. Doesn't have to be the same make or model, as long as it's a G-Body. Malibu, Monte, Regal, Cutlass, Grand Prix, Bonneville, Lemans Wagon and Century Wagon.
Hope this helps. ...