Petwriter, I haven't not published a book, as of yet, but I did minor in History in college and had to do history research at length and write VERY long winded boring papers on them to prove that I read all my sources.
If I were going to write a book in that fashion, of course making it more interesting, I would do the research the same way. (The internet only became popular when I was a soph.) I found that section in my library. I looked at every single books table of contents. Selected the books that didn't bore me to tears and started to what I call 'heavily skim' them to see if they had the info I needed. Believe it or not most of them quoted the books I left on the shelf. HA HA! Once a book caught my interest in more than one or two places I would read more intently...taking notes as I went.
I would google your topic, but you have to look further than the first page of websites. You have to google it using more than one term or phrase so it will bring different results. Or type, "Books written about..." and then check those books out. (Plus you can use it later for writing about your competition!)
As far as articles paper or internet if they give me enough information I tear them out or print. I highlight the info I want to remember, put them in a three ring binder, separated by pages of notes of what I was thinking while I was reading that article. This is usually where all my book brain storming goes...things you don't want to forget. Or areas you don't want to forget or look up later. That way it goes right with the articles in the order I did the research.
It works for me to go in order because if I get off too far in one direction I look back at where I started to stray, read that article again and go in different direction. Kind of a refocus.
In the front of the three ring binder I keep blank paper. I start the beginning of an outline and add to it as I progress, never erasing, just adding. If I take anything out, I put it at the back in case I might want it later. I hardly ever delete or throw away anything until I am completely done with a project.
Hope that helps....or at least is what you were looking for.