Eric Enge on the value of outbound link in your web pages:
"Publishers of authoritative sites almost always care about their users. They spend time thinking about increasing content quality and adding new content to their site. They are not afraid that when they link to someone else, they will lose traffic that will convert into business for them. They know that the links they send to others will mostly be used by people that are not finding on their site what they are looking for (so there really is very little to lose).
As you are researching on the web to learn the things you need to become an expert, make note of the sites that help you the most, in particular those that are not your most direct competition. Cite these sites as sources along the way. Your visitors will appreciate your site more, and you will make a much more attractive target for other authority sites to link to." Credit: seomoz.org