Just a general comment for those who haven't been. Sun n Fun is kind of a junior varsity Oshkosh with (nearly) as many airplanes and not (quite) as much hype. It is the other "biggie" for experimental aircraft each year and used to even be sponsored by the EAA but liability issues stopped that. It's the first "big" air event of the year and the weather is usually quite good, tending toward blue skies and warm to hot days. There are three basic ways to attend: Drive in, fly in, or fly in to one of the many nearby airports. If you fly in to Lakeland, be sure to read and heed the NOTAM for the no-radio entry rules (just like at Oshkosh). You can camp and either walk or take the free trams that constantly move people around the airfield (it's quite large). Or, you can fly in to Zephyrhills, Plant City, Bartow, etc. and rent a car and hotel it. I've done all three and they all work. FWIW, the entry route/pattern might seem a little daunting, but actually it's easy to fly.
HBC does stand for "home-built camping" and as others have said is mostly RV's. If you fly in for the day or longer but don't care to camp, they will put you in HB (home-built) parking which is right along the main runway. Just follow the "rules" and have a readable card that you can show the taxi-directors so they will know your intentions. HB parking is "up front" and features a nice mix of experimental aircraft, but it can get a bit hectic in there (and dusty/sandy too) since a lot of people taxi in and out during the times the field is open (before and after the airshow events).
There are flying demonstrations, warbirds, etc, etc. All-in-all a great time, but if you are like me and my friends, probably what you are really coming for are the commercial vendors (and the "show deals"). The four big side-by-side permanent buildings you can see in the overhead pictures are all for vendors and they will be chock full of EVERYTHING you need (and a lot you don't). Sun n Fun may be second to Oshkosh in some respects by it's ahead of just about everything else. Don't miss it if you don't have to.
P.S. I have nothing to do with Sun n Fun except that me and my flying buddies all like going there.
Enjoy...