Take a look at the US ski team BASE test book and video. That will show you which skills to teach. The book "Skiing and the Art of Carving" will give you lots of drills. Kids will get bored with drills though. So mix in a lot of directed free skiing. Kids need to build up mileage on skis, They become real impatient when you stand around talking at them. So keep the drills simple, explainations simple.
Skiing on one ski.
Skiing on inside ski only.
Skiing on outside ski only.
Skiing on outside ski, inside ski lifted high (stork turns).
Skiing without poles.
Skiing with one pole.
Moose turns, skiing with poles held on head like antlers.
Skating without poles
Skating figure 8s.
Double pole plants.
Constant double pole plants.
Moguls and jumps, let the terrain teach.
Kids don't necessarily need direction every run in a properly set course. The course should be set to teach them something, (ie rhythm changes, tuck turns, fall away turns, gate combinations/ tactics, flush to open transitions, tight turns, round turns) too many coaches just set a generic course with no goals for what the course is supposed to teach.
I would emphasize GS courses for kids that need to learn line/tactics and carving. Slalom is probably best trained in short drill courses rather than full length courses. It's too easy to get off your line and then spend the rest of the run practicing skiing a bad line.
USSA BASE test book available here.http://store.yahoo.com/ussa/edbook.html