I haven't been camping since Reading Festival 20 years ago. All the families at DC's schools are obsessed and go all the time. We've swerved it until now but have agreed to go on a camping weekend in a few months with 30 (!) other families from the school. DC are 5 and 7 and I know they'll have so much fun spending a weekend in a field with their friends. Seasoned campers, help me. What do I need to buy?