Group Learning

So i'm thinking about groups, colaborative thinking and working with students and teachers in these settings. How do I make the most use of the power of these networks? How do I assess? As a computer teacher, it's important for me to ensure that each student is getting fair attention, but not all students are alike. I have to admit, I have not done much with my students in the way of them working in groups. I like it in theory and hope to integrate it soon. It does present it's challenges. To me it seems like more work and an opportunity for good students to succeed and goof offs to goof off.