There are many tours that head out to these tunnels, but ours was lead by a guy nicknamed John Wayne, who had a strooong accent. For example, rather than saying "Ladies and Gentleman" he would just say "Lady Gentleman". Or "First... Chicken..." rather than second, but don't asked me how that worked out. Me and Kirbie got the giggles.
There were many groups at the tunnels and it seems to be the only way to do it, as without a guide you wouldn't have any context to the place.
There are displays of how the Vietnamese were very resourceful in creating weapons from bamboo and also on show are some of the traps they used against the enemy, which they will demonstrate for you (minus human in trap).