How could I apply group work into my classroom?

The easiest way I can think of doing this would be by using the lesson plans are group has created. Although it's not perfect, for the most part the unit we just created could be easily applied in a classroom. Every one of our lessons involves group work and the plans we have laid our clearly explain how to carry out the proceedures. As far as assessing student's work, I would use a rubric. Also, I would have students give their other group members a grade based on their performance. Hopefully when I finally get a teaching job I will have a reasonably sized classroom and a block schedule because I think these lesson plans could have the potential to become very difficult to carry out in a large class and in a short amount of time.