We have been going to St. Andrews State Park for over 40 years: first in a tent and now, in more recent years, in our fifth-wheel. I can answer almost any question you might have, so send me an email (use my PROFILE -- click on my user name) and I will respond promptly.
I just made reservations last night for our next visit to St. Andrews in May of 2006.
http://www.reserveamerica.com/jsp/co.../newindex.html
We prefer the "Pinegrove Loop", but there are many good sites in the park, many directly on Grand Lagoon. You will have to drive (or long walk) to the beach, but it is one of the best IN THE WORLD. Panama City Beach has all kinds of "ammusements", but that is not our cup of tea. Still if you have children or teen agers that is a plus. Let me know if you have more specific questions.