First of all, you must have space for co-sleeping if you are planning to let a lot of kids come and co-sleep with you. You might consider having a bedroom consisting just of beds. You won’t see the floor and cleaning will be a hassle but at least you will all sleep good and comfortable.
Make sure that small babies get the safest space and that everyone knows just where they are allowed to co-sleep. You decide who sleeps where and if they don’t stick to these rules you simply pitch them back to their own bed.
Let the kids start sleeping in their own beds and explain to them that they are welcome to yours but only if they come very silently and let you sleep. Make a rule that says that co-sleeping is allowed but it is not allowed to make noise or wake Mom before there is light outside. Even very small kids can understand this reasoning and they will be happy to oblige.
Don’t overdo it! Ask yourself if you really enjoy the co-sleeping. If it gives you good rest and you are not bothered by sharing your bed it is great but if it is difficult for you it might be a bad idea. You shouldn’t co-sleep because all of the popular psychologies tell you that this is the best. You should do it because it is the best for you!
If co-sleeping with many kids drives you nuts you need to kick them out of the bed gently but firmly. Perhaps a mattress on the floor will do till they get that the best place to sleep for them is in their own beds. If you have been blessed with many kids you should also consider that they can co-sleep without you!