A friend of mine is throwing together an impromptu gaming group, with himself as the DM. The majority of the people in the group are more experience players than he is-- and it's his first time DMing. The first session was a bit of a mess. He was thoroughly unprepared, and he has an annoying tendency to tell us what our characters are doing, instead of letting us do so. As it was his first time, I wasn't going to comment, but I had to stop myself more than once from saying 'But my character wouldn't do that!'.
Any suggestions on how to help him be a better DM without treading on his toes in the process? I've gamed a lot over the years, but I've never been in this situation before-- good or bad, the DMs have always been experienced at least. I've never dealt with a first time DM before. I want his experience to be enjoyable, but he does need a lot of help, too.
(cross-posted to dnd_women