How do I know where my Archaeology dig sites are?
Solution 1:
There is a finite list of Archaeology digsites. Your 4 active digsites per continent will always be drawn from that list. A comprehensive listing of them can be found here. Not all zones have digsites, but most do.
You should be able to see your active digsites while looking at the continent map. They'll be marked with a small shovel icon: 
While the shovels are not perfectly precise, they're close enough, and once you get nearby, you can look at the zone map to see the exact boundaries of a dig site in question.