Aha - now you are in my territory as I'm an Oracle DBA by trade!!!
As a home user - unless you have excess capacity on your machine (*), then the Access database is the best route to follow. You have a number of routes available here as regards sorting the documents - these include (in theory) using the meta tags of the documents themselves for dynamic searches.
The basic method, I'd have used, starting from scratch, involves assigning unique keywords to the documents then assigning the document file names to these key words. However you say you have started using an Excel sheet - well you can either use the Excel sheet as a search reference or import the sheet into a table within Access and search via that.
Sounds a bit confusing, I know, but with practice it gets a lot easier. If I can help you with the donkey work/setting up at all feel free to ask.
(*) IF you do have excess capacity then you can down load Oracle 9 Lite/personal edition free from the http://www.oracle.com web site - this allows you to include the content of the Word documents within the data base itself.