1.Books. Begin with books. History books. Restoration guide books. Manuals, both factory and aftermarket.
2.Clubs. Find a club that specializes in what you have.
3. Vendors. Find knowledgable vendors. Often, their personael can be very helpful.
4. Forum sites. Which, obvoiusly, you have begun.
Your first task, having learned EVERYTHING you can BEFORE starting disassembly, is to take the thing to bits and bag, tape, and label it all. And, take pictures. Take so many digital pictures that you are sick of looking at them, as you take it apart. You'll thank yourself later, for sure. Arrange these pictures by subject in files on your computer. Believe me, I've found out the hard way just how annoying it is to go through four hundred thumbnails looking for the orientation of some small component which could go in half a dozen ways.
We'll be here to give what advice we can. Enjoy the process. That's why you got into it.
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon