One of the ways I research for my fiction writing is to read biographies/autobiographies of people in the same profession as my characters. For example, half of my first novel takes place on a modern-day working cattle ranch. My shelves are full of books detailing this way of life. I also subscribed to (and still read) various magazines related to ranching. But there's nothing like hearing about a profession in the first person. It's learning by immersion, mostly. I came to a point where I could imagine my settings based solely on photographs and descriptions, and my character's voices came naturally because I truly understood what they would be thinking.
For settings, there's nothing like visiting in person. However, I believe it IS possible to learn about a setting from your armchair.
One potential danger with research is to never start the writing because you're so consumed with researching. You must start writing, sometimes even when you don't feel you have enough research. During the process of writing questions will arise, and that's when you go searching for a specific answer. Often the best way to find an answer is to pool your friends. One of them will probably know somebody who will know the answer.