first thing is go to a good bike shop and have them fit you for a size
try a few brands and styles, ride them around the parking lot, then take note of what brands and what size in that brand you like

unless you are strictly on paved surfaces a road bike is not my favorite choice
a mountain bike with road tires on it is pretty good for all around use, riser bars and a short stem will give you an upright seating position so its more comfortable and not as aggresive

hybrid or crossover bikes are the inbetween, and i hate them
they are great for what they are designed for, but i beat the shit out of my bikes, and they arent designed like a mountain bike is for abuse

what kind of budget are you looking at?
what is your biking style, relaxed, aggressive, do you hop of of curbs and shit, or do you relax and stay on the smooth stuff?


and never, ever ever ever ride ON the beach, sand in the chain/hubs/bottem bracket will fuck up a bike faster than anything else except submersing it in salt water