Wikipedia and books, depending on the subject matter and my degree of interest. For example, I’ve been reading historical research books because I love history. If it was something about the moon, it’d be Wikipedia and good enough.
You have to set a goal of what you want to understand and why you want to understand it, then read accordingly. If your goal is to know the usual number of eggs laid by a bird because you are trying to identify one from its nest in your yard, sure just read some Wikipedia and maybe read its sources. If you need to understand a broad topic in the social sciences in order to do your job or organize politically, well sucks yo be you, you need to spend months to years getting a handle on the various schools of thought and approaching them humbly and critically, reading many books.
I read everything I can find about it, especially if its people arguing thoughtfully, or sharing their advice/experience, or if its about the history of the topic. I get kind of obsessive about researching things so I usually come at a topic from a lot of directions.
I watch videos and read articles and use LLMs to give me the key points to grasp the basics. Then build upon that knowledge with more focused learning.
Why do we have teachers then? Listening and watching is absolutely a valid strategy of learning. You just need to make sure that the speakers are trustworthy on the subject.
Probably meant don’t rely on youtube, (as people produce fake info) while text books are rypically vetted, except in USA where Texas writes the curriculum supporting oil and gas and denying clinate change–and the other states purchase the Texas curriculum
Reading papers and contacting people in that field. I’ve found that university professors can especially direct you to materials in their field, and even like to chat about it sometimes. Half of my book collection was found this way.
A review paper from a reputable journal. The Annual Reviews series was great for this. Some of the Nature journals also used to run mini-reviews associated with research papers in the issue.
Sorry, stupid reference. In seriousness though, type in a topic into your library’s search and start browsing, check out a few that seem useful.
I’m an academic and I find my University’s library useful for finding knowledge on a new topic. If an introductory textbook exists on the subject, can be a good starting point.
For Most hobbies though, youtube is a great resource. I’ve gotten into woodworking and fishing, and youtube is a superb resource for information.
Just sit at the library for a while, sit near the shelf that has the topic you’re interested in and grab a few books at a time and go through them to see if any seem like the right book
Ask the librarian nicely and they’ll probably be able to point you in the right direction. Cataloguing information is kind of their thing, and helping people get access to that information is why many of them join the profession.
I was taught in school how to use the library catalog. It was considered essential, for success in life, at the time.
I actually do know how to use Dewey Decimal, if I haven’t forgotten.
In these modern times, there’s generally a PC near the information desk, with the browser home page set to a library catalog search tool, specific to that library.
And as someone else mentioned, we can ask the librarian for help, when we don’t find what we need. I actually shortcut the process and ask for a quick lesson in how to use the search, if I’m feeling uncertain.