Class that make up a division, what accounts are involved

Hi:

In QB 09, I am trying to set up 3 different departments in my QB. We have a cleaning service. The 3 departments are 1) residencial cleaning service, 2) commercial cleaning, 3) carpet cleaning.

They all have payroll and share many administrative expenses.

I have set up the Classes and attached a few items to then but I do not know how to get the information to the general accounts. When I pay a bill and it hits two of the accounts, how do I show that?

Thanks.

Dave