There are any number of awesome guides to group rides out there. As opposed to re-inventing that particular wheel, we are posting some links to those guides for your edification!
– http://www.bamacyclist.com/articles/groupridetech.html
– http://www.active.com/cycling/articles/basic-skills-for-group-riding
One day we will write our very own guide to group rides but for now you can check these out as well as our FAQ about our training rides.