This is some information that all metal detectorists with access to the World Wide Web should have available :-

Museums Libraries
Portable Antiquities Scheme (PAS) www.finds.org.uk
PAS Finds Database http://www.findsdatabase.org.uk/
     Uk Detector Finds Database http://www.ukdfd.co.uk/index.html
 
Maps
Google Maps www.google.co.uk/maps
Google Earth http://earth.google.com
Magic www.magic.gov.uk/website/magic
Old Maps (going back to 1885) www.old-maps.co.uk
   
Organisations
National Council For Metal Detecting www.ncmd.co.uk
Federation of Independent Detectorists www.fid.newbury.net
UK Detector Net www.ukdetectornet.co.uk
     
Magazines
The Searcher Magazine www.thesearcher.co.uk/
Treasure Hunting Magazine www.treasurehunting.co.uk/
        
Metal Detector Links
Metal Detector Reviews metaldetectorreviews.net
   
Clubs
Gold Coast Treasure Hunters www.gctreasurehunters.com/
Go metal detecting.com http://gometaldetecting.com/
     Michigan Treasure Hunters
http://mth.greatlakesmetaldetecting.com   
Great Lakes Metal Detecting http://greatlakesmetaldetecting.com/
Amarillo Prospectors  & Treasure Hunters Association http://www.amarillotreasure.com/default.htm