Your local friendly instructor conducting the DM class should be able to help
you with those kind of questions. I know, I know, you asked the people of this
forum, but as a DM, I would highly recommend purchasing the Instructor Guide.
Study it, because if you are as fortunate as I was when I became a DM, you will/should
be assisting in a lot of classes, if you choose to do so. Go to every dive shop in your area
and let them know you are available to help. It's the best way to learn the
system. Once you do that for a year or two, look at becoming an instructor.
I found it very beneficial to DM for a number of years and assist with instruction
that when it came time to fill out the questionaire in the IDC manual, it was pretty easy.
That is if becoming an instructor is the path you wish to take. As a PADI DM, you will be
eligable to teach a number of classes.
Some of my favorites are Discover Scuba (After you have been certified to teach it as a DM)
as well as Scuba Review for those already certified.
I also found that as a DM, you get perks, like discounts or free entry to parks, free refills,
and a network of people all over the place. Being a DM has
been a rewarding experience for me. Good luck on your class.

Lars
"Let's go Diving"