Geoff,
I'll echo what the others on the World Cruising website suggested.
San Carlos, just north of Guaymas offers a good spot to put in. It's one of the places many cruisers use to ship their boats back to the U.S., overland, via flat-bed semi-trailer. The folks at Marina Seca there have been involved in trucking boats north for many years. You might want to consider that as a place to begin your
cruise of the
Sea of Cortez. Whatever you decide, you'll have a memorable time in one of the best cruising grounds in the world. Great sailing...Pete