God I miss TCC
I took a group of seven "beginners" out two weeks ago for group riding 101. We covered 32 miles in formation with clear rules for calling. Rather comical, but I make the group walk through the maneuvers in the a car park before we hit the road. Then it is real-time coaching, with stops to assess how the group is doing. A little raggedy at the start, with two faster guy who I had to break up and continually tell to "ease off" and "soft pedal" (coasting is not allowed), but smooth and fast by the end, faster than some of the riders thought they were capable of riding.
We have had significant growth over the past few years, and have group riding standards that new members are required to meet. It doesn't matter how fast your ironman time was, if you can't ride in a group, then you'll be riding with the beginners and me or another ride leader until you can!
Once you've shown you are safe in a group, you can move to whichever group you want. This may be the hammerfest fast boys, or a steady semi-social group. All but the fast group have a no-drop policy. We don't leave people behind, but enjoy a sprint now and again.
Make your expectations clear at the beginning. Give feedback on how they are being met. Enjoy the ride, and the few moments when it really does feel like flying.
I would NEVER have considered racing if I hadn't joined a club, group riding gave me the confidence to have a go.