You might want to peruse the Jutland wiki:
http://jutland.wikia.com/wiki/Distant_Guns:_Jutland
This has been put together by players, not SES, so I can't say it's 100% accurate, except for where it quotes me
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In general, all the RN dreadnoughts and most ACs and AMCs are at Scapa. All RN BCs and most CLs are at Rosyth. The modern RN DDs are split between Scapa, Rosyth, and Harwich. The RN monitors are at Dover. There are scads of RN subs and obsolete DDs and TBs scattered along the east and south coasts of the UK.
For the Germans, pretty much all surface ships are at Wilhelmshaven, although there are some in Flanders, with detachments of fleet DDs there at various times. Most U-boats are at Helgoland, at least to start with, although there are some (mostly smaller types) in Flanders. The Zeppelins flank Wilhelmshaven on both sides.
The French have their main concentrations at Cherbourg and Dunkerque, but have smaller units at other ports. Except for a few DDs, all French surface ships are small, old, and weak.