Excel novice - Needs to create master billing list from multiple workbooks

First of all, let me state that I am a complete Excel novice (eg. haven't used it for anything more than charting data in high school science class). Detailed or even step-by-step explanations would be appreciated.

I'm trying to create a master billing list for the firm I work at. Each employee has their own workbook that they update every time they do something for a client, noting the task/time spent on each client (since they all keep their spreadsheets open, it isn't possible to use a single workbook with multiple sheets). For example, EmployeeA's spreadsheet might look like:

Client	Hours Spent	Task
ClientA	.5	X
ClientB	2.5	Y
ClientA	.25	Y

Employee B's spreadsheet might look like:

Client	Hours Spent	Task
ClientC	3	M
ClientD	3.5	N
ClientB	1	O

I'd like to create a master list that compiles the data from each workbook into one list, organized by client so that it's easier to bill the clients for the work done for them. From what I've read, a pivot table is the best way to do this. Using the Pivot Table Wizard>Multiple Consolidation Ranges option, I've been able to create a pivot table that adds the hours for all the clients correctly, but wasn't able to get it to display the tasks as well.

I'd also like the pivot table to be a persistent, updatable file - eg I don't want to have to go through the pivot table creation process every time, it would be nice to just open the file and click refresh/have it auto-update with the current data.

The master list might look something like this:

Client	Hours Spent	Task
ClientA	.5	X
ClientA	.25	Y
ClientATotal	.75
ClientB	2.5	Y
ClientB	1	O
ClientBTotal	3.5
ClientC	3	M
ClientCTotal	3
ClientD	3.5	N
ClientDTotal	3.5

Thanks for any help!

Anybody have any ideas?