Booking travel

I'm in the middle of the hell that is travel booking. Well it's really not the actual booking that's a pain - I've got my ticket through ebookers and they've been superb - I've had no problems at all with them. What is difficult is arranging people. Because I'm staying with friends rather than in a hotel or something (though that might just happen at the rate things are going), I have to coordinate so many people at once to try and slot everyone in, without pissing anyone off by making them think I don't value their time or their initial commitements.
I'm going to be volunteering on an organic farm for some of my time in the states and the family that runs it can't have me with them the first week I'd expected to help them out. So all my plans have to be bumped back a week, so I have to organise every single person who I'd asked before about the initial dates to try and do the same things as previously thought out, but a week later. This is a pain.
I hope it's worth it. I've never met the family on the farm so I don't know if they'll be mad or whether they'll be my best friends in the world. They sound cool though when I talk to them on the phone. I hope it all works out. Two weeks away anyway - the start is drawing near.