I have sailed there several times, it is an easy sail, well marked to Rebecca Shoals, then easy entrance once you get to the yellow boundary buoys (go around to the north).I have made the entrance at night several times, it is well marked. The north pass was closed for a few years, but was open again last time I was there, (July of 2009). They are now pretty particular where you anchor and have a mark on Bush Key that you need to anchor east of. if you draw much water stay a bit south of the docks. You can go aboard the head boats that come in during the day and buy cold drinks and sandwiches. Also, be aware, a few years ago, I was taking my dog ashore in my 7 foot inflatable with a 7 hp motor and one of the rangers coming in on a seaplane gave me a 100 dollar ticket for making a wake in a "no wake zone". Also, make sure you take a trip over to loggerhead Key and snorkel on the reef called "little Africa" it is beautiful. On the way there you can stop at the Marquesas, it is quite shoal but good bonefishing.
Have fun!
Michael