Total Newby Workout Needed Quick!

I am working on a masters swimming story for Men's Health, and my editor wants a basic introductory workout that guys who basically know how to swim but aren't swimmers to give the sport a try on their own. Since there is such a huge variance in skill levels, etc., I didn't want to give times for sets, etc. but maybe come up with some basic rest intervals. Anyhow, I am desperate for ideas here. If you have coached neophyte masters, or have been a neophyte master yourself and can recall an early practice that inspired you, please let me know as soon as possible what this is. I was thinking of the following basic approach: warm up possible drill set main set (probably 50s with 10-15 seconds rest) kick set cool down The whole thing designed to last maybe a half hour or so. The idea is to let these guys try it on their own, in a way that they might actually like, then urge them to look into finding a team. Thanks for your help!