I'll be there leading my extended family group of 12 people. 3 children - ages 5, 8, & 8. Five 30 somethings (me, my DH, my 2 bros. and 1 of their spouses), three 50 somethings (my parents who are divorced and one of their significant others), and my almost 80 year old grandmother.
As for tips, definitely get to the parks early and make priority seatings for any restaurants or character meals. We're renting a house and we're taking every 3rd day as a sleep in and non-park day. The other days, we'll be at the parks from opening to close with a PS for a leisurely lunch as a break on most days. I'm the designated planner of the group (of which only 3 are first-timers), and I'm basically telling everyone which park we're going to each day (avoiding early entry park), what time we need to leave the house each morning, and what time and where our PS meals are. Once we're at the park, I'll let everyone know where my immediate family is going and that they're welcome to come along with us, or they can go do their own thing and just meet back up with us at meal times.