now adays it's okay for people to just boulder and you won't have to worry about your kids getting hurt or in dangerous or scary situations. Listen to me and keep it 'close to the ground'.
I've never taken a class, or hired a guide. I've taught myself, and both of my children to climb, and we are all still alive and climbing. Finding a place to get started can seem a daunting task when stepping into the vertical world. Purchase a book on knots, and get practicing. I suggest a small yellow paperback book called "Knots for climbers", written by Duane (can't remember his last name). I believe this is a good starting point. Arm yourself with as much knowledge as you can before going out. Nothing compares to real world experience though, so take it slow, and be safe. It will take years of climbing before you become proficant. Be patient, and good luck.