You spend a lot of time on the range but there is some "class" time too.
They'll teach a bit of American History (something that the youth of today needs to learn anyway), a bit of the definition of what it means to be an American Rifleman and some info on proper shooting techniques.
Then its a LOT of range time. A .22lr is fine but you'll need a center fire rifle for the longer distance shots. I suggest a bolt action for both guns but I have to admit I attended with semi-autos. Don't expect to be able to go out there and just blast away though. Its CONTROLLED fire. Its a great learning experience though and in the end it'll make you a better shot. Oh I almost forgot, bring lots of ammo for each gun.
This would be a great opportunity for you and your kids to learn something together and form a strong bond as father and children. You should attend with them and learn/shoot alongside of them.
The only thing to worry about though is then that you'd need rifles for each of them as well as yourself. You'll also need a good mat for laying on (most of your shooting is done prone) and a good shooting jacket with re-enforced elbows. Aside from that you'll need a waterproof/weather proof cover for the guns and you'll need to make sure your rifles are well lubed and oiled. You'll shoot regardless of weather conditions - rain, heat, snow etc. (which also means you'll have to be properly prepared for said weather conditions).