To be honest I can't see anyone learning the game efficiently if they don't read the manual, except if you maybe played SC or 688 before DW or have some knowledge about modern naval platforms and tactics. I didn't find the manual hard to understand and comprehend.
With that said, the TACMAN mentioned by Janus makes for some good reading and goes into the tactical side of the game a bit more than the manual - which most of the time just tells you how to push a button and not WHY you should.
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