The answer to this topic is very simple and comes down to two things:

1. Work extremely hard 

2. Using connectors to gather clues and unknown information

There are always people who seem to have their ear to the ground and know all of the recent news. Some of the really good ones even know of things that haven't happened yet, but will. How does this happen?

Word of mouth is not published in the paper or online. Word of mouth is a conversation between two people where many times information is exchanged that is unknown to most people. It could also be known as a secret. One person may say, "I've learned from a contact of mine that one of their key assistants is leaving next month to take a job at XYZ University." This is an example of a piece of information that could not be found anywhere else. But, because of a contact, you learn valuable information that could have an impact on your future. 

I will warn you from being a rumor mill and talking on the phone the most of the day looking for scoops. A lot of people do that, but it' a good way to get fired, not hired. By using your contacts, and their contacts, you will find out about many situations far ahead of any advertisement or job sites online. Be profession, be courteous, and if it's a "secret" make sure it remains one.