International

• EarthCache – Virtual caches that teach a lesson.
• Geocacher’s Creed
• Geocaching.com – Geocache listing site.
• Geocaching Online – Offers Geocaching resources, information, events, how-to articles and more!
• GeocachingPolicy.org - Resource that keeps track of published poilicies regarding geocaching.
• Groundspeak – The company that runs geocaching.com, waymarking.com, and other sites related to outdoor GPS pastimes.
• Handicaching – Improving the accessibility  of geocaching for the disabled.
• NaviCache – Geocache listing site
• TerraCaching – TerraCache listing site that emphasizes the quality of its caches through a rating system.

Canada

• Parks Canada – Parks Canada page on geocaching

Alberta

• GeoCaching Edmonton -  The Edmonton Area’s GeoCaching Resource and Discussion Forum
  

Ontario

• Central Ontario Geocachers
• Golden Horseshoe Geocachers
• Halton Hills Chamber of Commerce – Article about local geocaching
• NorWest Ontario Geocachers
• Ontario Geocaching Association
• Ontario Geocaching Podcast

Blogs

• Cache Mania – A Canadian geocaching blog.
• gordon.dewis.ca – Ottawa area geocacher whose personal blog has a geocaching category.
• Gunny’s Cache – A geocacher in Okinawa
• Muggles don’t scare me! – A geocacher from Ohio
• Queens Borrower’s Blog – Geocachers in B.C.
• Rhondle’s Geocaching Blog – A Perpetual Account of  our Geocaching Adventures – Geocachers in B.C.

Shops

• Cache Advance – Geocaching supplies based in Spokane, Washington, USA.
• Landsharkz.ca – A Canadian geocaching supplier.

Other

• Ed William’s Aviation Page – Useful utilities for navigational calculations.
• FizzyMagic.net – Has some geocaching utilities.
• GeoCheck – Check solutions to cache puzzles.
• GeoChecker – Check solutions to cache puzzles
• MathCaching – A geocaching inspired game using math problems to find internet based caches.
• Waymarking – A scavenger hunt for unique and interesting locations in the world.
• Wherigo – GPS enabled adventure games.
• Wikipedia – Geocaching entry.