Here is an article "Diigo在華語教學上的妙用." It briefly introduced what Diigo is and how to use it as an instructional / learning tool. Hope it can help you to apply Diigo in class.
Using Diigo, you can both easily bookmark your favorite online resources in the cloud and annotate, share, and collaborate in new ways! This hands-on session will introduce the Diigo collaborative research tool and explore several practical applications for implementing collaborative resource sharing in the classroom.