Hi, while we're on the subject, how does one go about finding out what others have written about Thayer, let's say, in their autobiographies for example? I haven't a clue of how to go about it.
Do you have specific autobiographies in mind? If not, if you have a list of his credits, look and see who he worked with and then take a stab at finding material by or even about those people (directors, actors, etc.). Biographies are sometimes better because they tend to be a lot more objective and if the author was any good, they checked up on the facts.
If you do, then indexes will help. If there are no indexes and sometimes there aren't, then short of reading the whole book, I'd skim through (e.g. he worked with such and such during a specific period of time, so find that section of the book first).
I think you'd be best off starting with reference sources, then going to the periodical and I&A indexes and databases, and books, etc. Anyone doing serious research is going to be spending quality time with the microfilm readers though