Hunting is an excellent sport to get into. You'll become well aquainted with patience and silence once you really indulge in an extreme hunt. Rifles greatly vary, but generally you can assume that they will be semi automatic and have different specialties. I would suggest you start out with a basic bolt action rifle. Go to your local hunting shop.
There are many different rifle cartridges for many different sized game. For big game, popular calibers include the .308, 30-06, .300 win mag. For smaller game, popular calibers include, .223, .22LR, 17 HMR, and the .204.
There is not enough room to name all of the hunting rifles in the world. I will go with my preference, a .308. The .308 is a fast accurate round that carries more weight than, say, a .223. If you are into deer huniting I would use a .308.