guys, I just created this screencast to answer Marina Bonani's question. It's about how to start bookmarking. Here you go. Remember you need to install Diigo toolbar, or "diggolet". Where do you find instructions to do that? In our virtual classroom. It's all there!
Excellent text that will really help you understand the concept of social bookmarking and the power it holds. The text is straight to the point and easy to read.