Creating links to multiple documents

Okay, so here is my problem. I work at a very small arena and I am trying to put together some Excel work sheets to keep track of our customers rentals. So far I have put together a sheet that I can enter the customers name, rental time, rental length, hourly rate, tax, total due, total paid and amount owing or on credit. I have formulae in place that total the amount due from the hourly rate and tax cells and ones that total the amount owing or on credit from the total due and total paid cells. What I want to do is set up a sheet that keeps a running account of how much each customer either owes or has on credit throughout each season. I want the data on this sheet to update itself automatically as I enter the data into each customers individual worksheet. I want to be able to open this sheet at any time during a season and have accurate info on how much each customer owes or doesn't owe without having to open each individual customers sheet. Is that possible and does anyone know how to do it? Thanks for any help you can provide and if you can't help, well, thanks anyways :)