First, do a search here on "white cap" and see earlier discussions about the boat.
Second, find the serial number of your boat, and in the research section of these forums, post a request for the build record of your boat under "serial number search."
Third, go to
http://forums.wcha.org/showthread.php?57-How-much-is-my-old-wooden-canoe-worth in the "frequently asked questions" section of these forums for a discussion of valuing a boat. While the thread focuses on valuing canoes, the same considerations would basically apply to your White Cap.
There is quite a bit of discussion about fiberglass instead of canvas, with most opinions against fiberglass. Again, using the search function should get you some information on this topic, and again, while most of the discussions will be with regard to canoes, much of the thinking is transferable to other boats that are/were canvas-covered wood.
That will get you started -- and don't be bashful about asking more questions. Further, don't forget that we love photos here -- both because they provide information useful in formulating an answer to your questions, and because we just plain like canoes and boats.