Okay here's what you do...
I am not sure if you have made your reservations yet but if you call the disney reservation line, you could book a grand gathering, this simply means that although each family has there own individual reservations, all reservations will be linked together with a Grand Gathering number, when you do this the resort does their best to keep all the rroms together and there are also special tours offered only for Grand Gathering Guest, the disney cast member at reservations will go through these with you if/when you book.
Afterwards, i would recommend that you sign up with tourguidemike.com he will help you with everything else. But if you opt not to that is also fine just start thinking about whats important to everyone ( must see's) then decide if you will spend all your time together or if you will spend some time apart.
Then Start thinking about what dinning reservations you really want and on what days, make your ADR (advanced dining resrvations) ASAP you can always change them later if you move things around in your daily itenerary.
After that your pretty much set.....so
1. Decide if a Grand Gathering would work for your group ( must be at least 8 people)
2. Book the Grand Gathering ( you will need addresses and phone numbers for everyone at time of booking so have that available, 1 person can book everyone, or you can have them set it up with your reservation only then pass on the grand gathering number to other memebers in your party so they can add themseleves. Dont forget to decide what ticket options you want.
3. Figure out what is important to everyone in your group and how much time you will be spending together. Sketch your itenerary
4. ADRS
I know it seems like alot but the staff at Disney makes it so easy. You'll be fine and have a good time.
feel free to PM me and Email if you need anything