To start with I suggest a 12 guage, this will give you many more options in ammo and barrles.
Unless your state requires hunting with shotgun slugs, I would suggest you buy a rifle for deer hunting. Slugs don't have a long range.
There are several good brands of shot guns, 12ga and 20ga, that will fit your needs. It depends on how much money you have to spend.
Check out the major brands like benelli, mossberg, and remington. Find the one that fits you best, The stock is the right length, one that when you bring it up to fire, the sights automaticly are lined up for you.
You can't go wrong with a major brand, and don't buy it at walmart or kmart, they only have the low end models. Its kind of like a plain jane camaro or an IROC, pay a little more and get some extras(vent rib, better stock, ect.) If you have a Bass Pro or Cabella's superstore you can check out a bunch of guns before you buy.