Though many are missing, equally many tithing collection returns are present.  In addition to Surry and Sussex, returns for which I have used frequently in my own research, here is a copy and paste URL that should take you to some of the available counties.  If this does not work, type into Google "Virginia colonial tithables county returns".
 
Here is the URL
 
http://www.google.com/search?hl=en&lr=&as_qdr=all&q=Virginia+colonial+tithables+county+returns

To subscribe, change options, or unsubscribe please see the instructions at
http://listlva.lib.va.us/archives/va-roots.html