Choose the location. Pick a place that's interesting, with plenty to see and do. If some of them have trouble getting around, it can't be a physically challenging trip with hills and steps.
Consider the weather and time of year. Summertime crowds can be dangerous for a senior. You don't want to deal with snow either.
Map out the agenda and schedule. The seniors need to know where they'll be stopping and when. Make sure you don't cram it full of things to do. Travel from one point to another may be slower than expected.
Hire a bus. Ask what it will cost for the trip. Add in the suggested gratuity for the driver.
Determine how much each senior will have to contribute. If you have a budget for the trip, great. If not, divide the total by the number of people you expect to go. Decide if meals are included or if they're extra.
Post a sign-up sheet for the seniors. Have a clear deadline of when you need their commitment and money, if applicable.
Determine handicap requirements. Buses have wheelchair ramps already--but it's helpful to know in advance how many seniors will need extra help getting around. You want to familiarize yourself in advance of the handicap accessibility of each location on your trip.
Meet, load up, hit the road and have fun.
