After Building the Explorer's Society Guild House and recruiting the members of the Explorer's Society the Archaeology skills will become available. On the table inside the guild house will be 4 books three stationary ones that open up the new skill trees and one book that tracks your skill progress and has descriptions for the three skill trees.
The Archaeology will go up by one every time you mine a archaeology Dig Sites or whenever creating a item at the Archaeology Station. For every 5 ranks in the Archaeology skill you get a point that can be invested in any of the three skill trees.
Information on each of these skill trees can be found at the following links: