1) Are you sure they are honeybees? Take a photo of the swarm with your cell phone and send it to the beekeeper you will call! See Identifying a Honey Bee below to see the difference of a honey bees versus other types of bees.
2) When did you first see the bees?
3) About how many one-gallon paint cans can you fill up with the bees?
4) Where are the bees located and about how high up are they?
5) Are they inside a structure?
6) Are they in a tight ball or are they flying?
7) Is anyone there allergic to bees?
8) Will the property owner be present?
9) Can the shrub or limb be cut (which is usually necessary to remove any pheromones left by the queen)? How large is the limb?
10) Have the bees been disturbed (sprayed or otherwise harassed) by anyone?