Visit several bike shops in you area, if you can or go to the next larger city that has a few. Test ride as many as you can. See what fits. See what you like, the seat, the pedals, shifting, turning, balance, breaking, acceleration, turn at speed, tight circles....in other words put them through their paces for your own good.
Try out hybrid bikes, road bikes, comfort bikes, mountain bikes...recumbents. Figure out what YOU like after all it is YOU who will be riding it, so it is YOU that must be happy.
Finding the right LBS is as important as buying the bike. If they want to push you into something quick then find another shop. If they let you ride many different bikes and want to listen and chat with you then you're probably at the right place.
I had my choice down to 4 in about 10 minutes and 2 weekends for the final 4, then I bought 2.