Ohh Newbies. It's so hard you want to encourage and make them feel welcome but keep your distance. I've did tons of Mass start races elbow to elbow tire to tire No problem. Get me on a "rec tour" with newbies and rec riders only and I am more stressed because they don't know what a straight line is, never looking backing before moving around and eventually I race ahead because I cannot stand the stress, go figure. Defintly give all newbies a good safety 101 before starting with a group. I did a racing clinic and we had to ride in packs and a new guy's bike would go in whatever direction he was looking sometimes at me when he was talking. Finally I told him to look straight and he laughed then the other guy in our group piped up and we both got on him pretty good. He took it great and improved alot! Most riders want the advice if you see them doing something wrong.

Good Luck!
Kim