There are a couple of points that maybe I can hit on…
Assuring the parents that the troop is boy-led, but adult-supervised, will be the first of many tasks. It's really hard for parents to "cut the apron strings"….there is no friendly way to say it. The parents have been involved in their son's Cub Scouting career since day one, and now it's time for you and your troop to take over…speaking from a guy's point of view, it's like a guy fixing up car for 4 1/2 years to get it to where there isn't anything left to do, but to admire it, but another guy wants to come along and take that car to the show. The guy doesn't want anyone but himself, to take that car to the show, but the guy also doesn't know what to do when he gets to the show…and then is disappointed when he doesn't have the best experience…
What I am getting at is, as a troop, educate the parents…hit them with the proverbial 2 x 4, "Mom/Dad, our unit does things this way…" and then explain all of this to them. Boy-led, patrols, PLC, and the heirarchy. Help them to understand, or educate them…that is what parents want. "I don't know how Boy Scouts works, but I am not going to ask. I will just do things like I did in Cub Scouts…" is what a lot of parents think. Oh, by the way…these conversations should happen on the den level, pack level, and the sooner the better. Education is the key. On a personal note, I am already talking to parents whose son's are in the 3rd grade, about Boy Scouts…in 8 short months, those Bears will be Webelos I, and ready for a whole new experience. Your troop should be there to help with that guidance and education.
Secondly, for the training manual for the behavior of the Scouts when Webelos visit, I have a really good resource…it's called the Scout Law, the Boy Scout Handbook, and the Scoutmaster's Handbook…
In a "top-notch" troop, the Scoutmaster leads via the Senior Patrol Leader…and that is where the adult intervention should start and stop. Any parent that has to get involved, and can't go to the Scoutmaster, well, needs to step back. The parent should trust the Scoutmaster to control the situation, via the SPL. The SM also keeps the boys inline with SM conferences, and using the Scout Oath, Law and by using the 8 methods of scouting effectively. It's nobody else's place to ever step in…in other words, it's the Scoutmaster's Party, he is the host and has delegated the activities to the boys…trust that his judgement is correct. Overstepping those boundries only undermines what he has been charged with, via the Troop Committee. The troop committee appointed the Scoutmaster, and was approved by the Charter Organization, so someone likes that person. If the SM isn't doing the job, then maybe a replacement is in order.
Sorry for the long-windedness, but sometimes I don't step off my soapbox soon enough
In essence, educate the parents of the Cubs that you want to recruit, and the Scoutmaster, Scout Law and Oath, and the books should be handling the behavior…