Dunno 'bout Maryland, but at least when I lived in PA it was illegal to hunt deer with rifles. In fact IIRC, single projectile weapons were not allowed, so even slugs in a 12ga I think were out. It's been 10+ years though since I lived there, so that may have changed, or I may have been told wrong info. Unless you know you will be at least 3 miles (preferably 5+ miles) from civilization a shotgun really makes the most sense. If you miss, or even have a AD with the muzzle pointed up at a 45deg angle you'll have a lot lower chance of hitting anyone. Couse, the downside is that means you also have to get really close before shooting, a lot closer than with most rifles.
Now, if MD does allow rifles for deer, anything from .243Win on up will do you just fine. I know some people on this board even use .223Rem for whitetails, but before you rush out to get a Mini-14 as your deer rifle, check state laws as some set .243Win as the smallest caliber allowed.
Rifles are really not appropriate for ducks, geese, and (I would assume) turkey. Main reason being is that you're typically shooting up at them as they fly (at least for ducks and geese, not sure about turkeys) and a miss means a bullet going for miles if you use a rifle. A miss with shotguns usually means the pellets going a few hundred yards.
So, unless you are willing to deer hunt with a shotgun, you'll need at least two weapons for that hunting. Shop the gun shows, gunbroker.com, auctionarms.com, and our own Buy/Sell/Trade forums here on THR for a good deal on whatever you decide to get.
As for specific rifles (or shotguns for that matter), I won't make a recommendation. My advise is to go to a bunch of gun shops, gun shows, and THR shoots. Handle lots of different rifles. Don't pay too much attention to the caliber of any particular gun. Don't let the salesman talk you into anything, whether that's his preference for a particular brand, or caliber, or action type or whatever. Throw it to your shoulder and see how it fits and feels. Work the action (for bolts, levers and pumps) and get a feel for how smooth it is. Probably a good idea to stay away from semi-autos until you have more experience under your belt. Ask if you can dry fire it a time or two to get a feel for the trigger (keep the gun pointed in a safe direction!!!). If there's an opprotunity to shoot it (THR group shoots, range attached to the store, etc) put at least 5 rounds through the gun. Once you've done all that with a couple dozen rifles you'll have a good idea as to what you want in terms brand, style and action type. Then decide on the caliber you want. That'll be hard unless you actually get to shoot a few different rifles, but I would recommend staying away from anything with the word magnum in the caliber designation. A .243 will kill a deer just as dead as a .300UltraMag (and waste less meat). The lighter the recoil the more you'll be likely to practice, and therefore the better you'll get at shooting that rifle.
FWIW, I'm looking into buying a CZ 550 in 6.5x55. There's another rifle or two that I'm also looking at, but the CZ seems most likely at this time. I've fondled a couple and really liked the feel of them. They're in my price range (+-$500) and they have the controlled round feed type of bolt action. The other type is called push feed, and I won't get into the differences here as that's like starting a 9mm vs .45 debate. Suffice it to say that CRF is my preference and that is purely a personal thing. The other reason I want the CZ is that it is available in 6.5x55. Why do I want that caliber? I already have a rifle in that caliber that I really like, but being a heavy mil-surplus gun it was not what I really wanted to take hunting. It's a very versitle caliber, doesn't recoil much, and has the ability to take almost any game animal in North America.
Anyway, that was the process I went through in making my decision. Good luck.
