Ask HN: Non-designer/developer UI/UX testing resources?

I've been asked how people "get into" being professional UI/UX software testers and what resources they can use to learn more. My answers so far have been things like "learn the names and functions of UI widgets", "study effective communication strategies" and read the guides on "how to write effective bug reports" and things like that. I've been unable to find any good books or comprehensive tutorials sites for those testers who sit down, try out software (and try to break it, record things they find broken/non-intuitive), and report their results. For the record, these testers are people who do not write automated tests, create test suites, set up automation tools, set up crowdsourced tests, nor design or implement the user interfaces. Everything I've found so far are for people designing, implementing, (automatically) testing, and outsourcing this work, but none for the actual people who do the testing. Lots of Googling hasn't turned up anything useful.