Dedicated to the collection, restoration, research and appreciation of all manner of clocks, watches, and sun dials. They have many resources to help everyone from new collectors to experienced professionals. http://www.nawcc.org/
Place for hints and tips on clock and watch repair. Also includes a Identification Photo Database with modern and antique clock and watch movements. http://www.bhi.co.uk/
Comprehensive global list of membership organizations of interest to collectors of clocks and watches and other horologists, both enthusiasts and professionals. http://www.horology.com/ho-membr.html
Watchsearcher is the biggest database of stolen Swiss luxury watches - check for free if a watch you want to buy is recorded as stolen or lost. Many loss prevention hints are also mentionned http://www.watchsearcher.com