There is no one way to do this, but there are more effective and efficient ways. Here is some advice....
Remember to just start where you are. Any of the resources listed in this guide are good places to start. Where you start, however, depends on what you already know. If you already have a book, a journal, an article, or even a documentary, then start by fishing through the content provided by that resource.
Author names - they have more work out there and usually have co-authors.
Book/Article titles - there are more resources out there using those terms
Journal titles - focusing in on a specific journal lets you be less precise with your search terms
Notes - bibliographies, references, footnotes, end notes, and citations for graphs and charts also provide a wealth of information that can be utilized for future searching.
Start where you are. Pick apart your research question if you haven't already.
Not everything written down is important to the investigation. Focus in on the most important...well, keywords.
Sometimes you may not need a word at all because it is implied in the effort itself. Some words need to be given more thought to see if they matter.
Every word you use can contain numerous other ideas. Maybe those ideas are more specific. Maybe those ideas are just ways to convey the same idea more precisely.
It's like a spider's web.