to add my .02 to eden: on the start, if you're unfamiliar with a group ride, you might want to stay towards the back............my first organized ride all those bikes starting out was a tad intimidating with people weaving all over the place trying to get started, clipped in, move to a better spot, etc etc. I had someone with me that was used to mass starts and he hovered close but it was still a little overwhelming.
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"