:When you are in a certain field of work, you are going to be doing tons of research. That means reading a lot of journal articles. (And when I say a lot, I mean it. When I did my thesis I had a stack about 5 or so inches high of articles I was reading.) So you get your main info by reading these articles.
:Once you read the articles that apply to you, you usually end up contacting the people who wrote the articles (or at least I did when I was doing my thesis).
:You make friends with them (as long as they aren't too cut-throat) and get to know what the latest developments are.