combining data from several files

[ESCIV]

Once again my ignorance shows....I'm sure I can do this with either a Pivot table or Template Wizard but I can't get either to do what I need! I have 3 files - one for each month in a quarter. Each file has 4 or 5 worksheets - one for each payroll week in the month. I now need to combine the quarterly information to get payroll expenses by department. How do I do this please? Thank you!