We started off talking about optimal research methods. There are substitutes for finding a person who is an expert on your topic, having a conversation and asking questions - but none are nearly as good, especially if you are dealing with cultural details. If you're going to be using Wikipedia, it's a great first source but you need to find contrasting sources, given that it can be inaccurate and/or tampered with.
If you are going to be dealing with a culture from an outsider's viewpoint, you might have an easier time. Most research sources turn out to be outsider viewpoints. Finding insider viewpoints is much harder. This is why conversations with real people can be great. However, if you're looking for something historical, it's good to go back to literature of the time to look for details. Putting yourself inside the viewpoint of a character who is unlike you can be hard. Research helps, but there is also an imaginative leap involved. Sometimes this leap is easier than others. If your narrator is the same as your character, there can be more challenges involved.
Primary sources (journals, recordings, etc.) are great resources for research. So are documentaries, books, and non fiction books.
Reggie mentioned that physiology impacts point of view. Research on Earth animals can help with this kind of detail.
Personal experience in a subculture or field of study (like Jay Werkheiser's expertise in Chemistry, or mine in anthropology and linguistics) is a great resource.
How much research should you really do? We hypothesized a fictional world with two moons, but had various viewpoints on how much research should be done on how two moons would affect worldly details like climate, tides, etc. If there will be no mention of any phenomena linked to the two moons, it makes sense not to go into great research detail. However, different story markets like to see different levels of research accountability (Analog, for example, would definitely want you to know about the planetary consequences of double moons).
Science fiction can seem to be a genre requiring more research than fantasy, but that's mostly an illusion. J.K. Rowling did an enormous amount of research when she was putting together the Harry Potter books, on everything from etymology to witchcraft, etc.
Accuracy in small details can be a great treat for experts among your readership. Easter Eggs!
It is easy, however, to get lost in the process of research to the detriment of the story. Keeping a strict criterion of relevance is very important to stay focused on your story. Research topics can grow out of a story, but stories can also grow out of research topics as well.
Worldbuilding, and the research involved in it, is different for novels and short stories, but not as different as one might imagine. I referenced my post about story worldbuilding being like walking through a house looking out windows, while novel worldbuilding involved leaving the house and knowing about what was outside.
As an example of intensive research by an author, I talked about Stina Leicht, who did years of research on Northern Ireland and the Troubles before (and while) writing her series The Fey and the Fallen. She even took lessons in Irish Gaelic. That research shows - in spades - in her work.
When you are working in a secondary world, it's often helpful to write short pieces set in various areas of the world as a form of research. Research on general scientific topics can be very helpful, but applying it to the secondary world requires a different mindset. I find myself doing mini-ethnographies of different social groups in my Varin world, for example.
Some more great sources include:
Nonfiction books (read widely!)
Children's nonfiction, for topics we have very little experience with
Public lectures and interviews (radio or podcast)
Thanks to everyone who attended! Here's the video: