As journalists coming into the ever changing world of the Internet, we've been faced with a task that is normally distributed to an entire room of people. Fact and source checking, editing, as well as creating and editing graphics to go in our stories.
Perhaps the most important of these, as of late, is the validity of the sources we use in our stories. As time consuming and tedious as it can be, checking the usefulness of your sources is essential to writing a good, interesting, and, above all, true story.
Choosing sources who have no agenda or bias is impossible, and it makes our jobs that much harder to write an objective story. Even as a journalist, it's almost impossible to write a completely unbiased/objective story, and having sources that are as close to uninvolved as possible only helps to make our jobs that little bit easier.
The use of secondary sources is something that, I believe, you must take on a case-by-case basis. If you take the time to check what they were cited as saying was not taken out of context or completely false, there should be no problem with using it. However, the point brought up by Tatge with our responsibility to readers is a good one. I think that, as journalists, we have a certain responsibility to our readers to dig for the information and report it from our perspective. However, I think including other journalists' viewpoints on an issue can bring a dynamic to our story as well give credibility to other journalists that we feel our readers should be reading.