i was the camping chairman for cubs and scouts for about 12 years so i have done a lot of this. cubs are pretty easy. make it simple. you don't want to get into the hardcore survival stuff with cubs cause frankly its not necessary. that comes later with scouts.
the way i did it was to come to a den/troop meeting with my full gear. backpack, tent, bag, stove, food, mess kit, fire starter, etc. i would break the pack down, set up the tent and stove and show them everything and how it worked. when they were cubs we had a hiking club and each hike we did something that the kids had to be prepared for. as cubs they all had to bring their pack with whatever was needed. when they got to be scouts, we did the same prep for overnight backpacking trips. everybody had a list and everybody was responsible for their own stuff.
as a side note, i also made walking sticks for all the kids as motivation to get to the "25 mile club". it was great fun. i miss it. i still collect nice little trees for sticks with the idea that maybe i'll get back into it sometime.
