I will start by saying what to stay away from. There are two things and they are, in this order, tires with aggressive tread and mountain bikes. With that out of the way you should look for a fairly light weight model "road" bike that allows for a rack to be attached to the rear. Almost all can have an attachment on the front. Any local bike shop (LBS) can help you see what to look for on the rear of the bike.
Handling hills is really all in you. If your legs are strong it will not seem so bad. However, one thing that will help you out is having an gear in the front. More gears on your cassette, the gears in the rear, will offer more variations but not necessarily assist you very much. Lastly you want smooth tires and avoid shocks. Shocks will absorb some of your effort making you more tired overall while not giving back much since roads are normally not full of pot holes. The slick tires will ensure that you are getting almost all of the forward force that you put into the peddles. I have given this advice many times while working at bike shops. I hope it helps.