I am looking to purchase a yacht to use as a liveaboard in S. Florida. Are there websites for monthly or annual rentals of a yacht to get the feel for the lifestyle first?
I don't know about websites but I would go into West Marine and pickup all the free magazines and newspapers that have classifieds as a place to start looking.
call some of the charter companies in South Florida. I'm sure some of them would be willing to charter you a yacht at a discounted price if it's not leaving the dock and you don't need the crew to go with it.