The first one has been covered, though specifically rather than generally: what each tool is for.
Like many teams, we have a selection of saws. Each one is best for a specific range of functions. We have “chop style” saws, a large abrasive cutoff wheel, one with a blade for nonferrous metals, and one with a woodcutting blade (does both crosscut and ripping, though used mostly for crosscut). We have a jigsaw and a reciprocating saw, each with a variety of blades. We also have a cordless circular saw, and of course the dremel. Selection of a saw and blade is dependent on the material, direction and length of cut, and the required precision. Similar rules apply for drills (corded vs cordless vs drill presses) and hand tools (socket vs wrench vs pliers; hammer vs mallet; metric vs SAE (5/32" != 4mm). One of the main things that needs to be communicated is that the dremel and the crescent wrench are NOT the answer to every problem - I regularly refer to each of these as being the “tool of last refuge”.
As also mentioned before, how to use each tool, and how to use it safely. Explicitly say what can go wrong when the safety rules are not followed - stories about flying metal and broken bits and saw teeth and safety goggles doing their job make a much better impression (especially on teenagers) than a simple “do it this way.” Related: tool inspection, tag-out, and reporting issues with tools so they can be resolved. (Though an unreported broken dremel did more to get the kids to use the right cutting tool than the talks in #1.) Also, any maintenance for the tools such as oiling steel blades both for lubrication and preservation and tensioning/changing belts.
Where are the tools kept? How to find them efficiently, and the importance of returning them to their home so they’ll be there next time they’re needed.
Another thing to cover is measuring and marking pieces for cutting. This is especially important when doing a large number of pieces or when the marker and the cutter are not the same person, so that it is clear whether the cut should be on the left or right side of a line. We also have a bit during tryouts where we show how it is better to measure distances from a common origin rather than incrementally.
Bottom Line: teach them what to do and how to do it, but (especially early) spend more time telling them what NOT to do - and WHY.
I thought so, too. I found out that you have to teach (at least some) people that the pieces being riveted have to be held tightly together, and the rivets have to be pressed into the pieces as you go; that you should place all of the rivets (or clecos if you have those) before you start setting them, and that rivets are most useful under shear, and are not the right fastener if the rivet will be under tension. A few don’t even seem to realize that the holes have to line up and the rivets won’t magically do that for you.
Edit2: related to several points above, and specific to versaframe work: Don’t drill a hole in versaframe without understanding why the pre-drilled holes aren’t in the place you need them. If the plans didn’t say to drill that hole, it’s more likely that you made an error somewhere else, and you’re only making things worse. This goes at least double if the hole is not along the centerline of the tube! We’ve had students cut angles too broad, then drill extra holes to make the gussets “line up”, resulting in a complete waste of both time and materials.