Janes 688I evolved into Sub Command, which was the forerunner of Dangerous Waters. Tutorial-type docs for DW or SC would, for the most part, be applicable to Janes 688I. For example, the Seawolves 'Blue Book' (available on the downloads page of my site) would be a good start for you.
Hope this helps!
(BTW, Janes F/A-18 is my favorite flight sim
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