Re: Greek cruise
I would think that during your first trip or two you will start making contact with locals and get better information at that point, esp if there are not good cruising guides.
Here's a Wiki link you may have already seen..
Greece - a Cruising Guide on the World Cruising and Sailing Wiki
Sailing Greece - free yachting and charter holiday guide to sail the Greek islands - yacht charters Greece
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
1984 Fast/Nicholson 345 "FastForward"