Just a few things...
-I would make sure to provide a 100% puppy-free place (perhaps crates?) for your seniors to go for a break. You may need to teach them to go there when they get overwhelmed with your youngster!
-Make sure you still spend quality time with your current dogs. I find it helps to keep their schedules as regular as possible when intoducing a new dog into the home. I know it can be very tempting to do nothing but fawn over and play with a puppy, but the intro will go much better if resident dogs still get the same amount of attention and exercise that they would normally get!
-Watch your puppy and adults carefully when together. Do not allow your puppy to get overly rough with your adults. I would personally allow the adults to correct the pup when they have had enough. But also make sure that the corrections are fair and not over the top! It can be really hard to know where to draw the line, but you know your dogs best. Trust your instincts! Also, when I introduced my newest dog, I had tab leads on everyone for probably 1 1/2 - 2 weeks just incase I needed to quickly grab someone! It may be helpful to do something similar to make it easy to remove a dog when needed.
-Feed in seperate areas.
-Watch everyone closely around toys and other valuable items.
-Feed/reward for good behavior when in the same room! If you have more than one person in the household, one person can have the puppy on one side of the room/babygate/x-pen/etc. and the other can have the older dogs. Feed really great treats (chicken, steak, cheese,hotdogs, etc.) just for being near each other. They should only get these treats when everyone is together!
-And of course always seperate the dogs when you are not home or are unable to supervise!
I'm sure others will have more advice!
Good luck! Hope everything goes smoothly and please share some photos when you bring Woofgang home!