Common Data Source

I use a common data source of HR information for the majority of my reports.  The data source is based on Excel files which I need to routinely pull and refresh.  My approach has been to use a common folder for these files, rather than copy them for each project I create. Is there a more efficient way to do this? There is still a level of manipulation that I need to do for new data, and I was thinking perhaps there was a better approach. Any thoughts?

Thanks,
Geoff