A somewhat belated response to this but if you want to know as much as possible about Fisher, then you're best off getting and reading the three main biographies.
Bacon, The Life of Lord Fisher of Kilverstone (II volumes).
Hough, First Sea Lord.
Mackay, Fisher of Kilverstone.
Then there are the three volumes of letters edited by Arthur J. Marder in the 1950s, and two volumes of naval papers edited by Peter Kemp for the Navy Records Society.
I always work on the basis that if you want to know something about somebody, you're best off knowing everything.