In my student years I was often amazed by reference librarians who helped me find relevant information even the subject was remote to his/her specialty (I was told so). They are knowledgeable in general and quick learners for sure. But more importantly, they know the strategy and logic when encountering unfamiliar subjects on their daily job. This ability is seen as one of the prominent characteristics of librarianship. It makes the reference librarian as a walking-encyclopedia, so to speak.
In a recent blog post <http://searchresearch1.blogspot.com/2015/05/this-week-conversation.html>, Daniel Russell of Google asks “What do you do when you need to learn about a topic area very quickly?” His take is to “look for groups of people interested in your topic.” Other people suggested sources and tools like Wikipedia, good keywords, professional associations, authoritative guides, blogs, and of course, Google search. I like to check Wikipedia for known subjects, e.g. classical music, and to search Google for just about everything. In most cases, the latter will include the former in search results. Dr. Russell will have a related talk “How to become an instant expert on a topic through Google” at the Investigative Reporters and Editors conference in Philadelphia. <https://www.ire.org/events-and-training/event/1574/1952/>