Van Pelt, Robert. 2001. Forest Giants of North America. Seattle: University of Washington Press.
I admit to a certain amount of bias -- I visited many trees in this book during its writing -- but this really is the most outstanding publication in all of human history on the subject of big trees, presenting information on the five to ten largest examples of the 20 largest species found in North America. The drawings must be seen to be believed; HERE is one example, of an extraordinary Sequoia sempervirens (Coast redwood). The range maps are the most detailed available.