If you've played any of the other Civilization games, this one will hold very few surprises for you. In some respects, Civ IV felt more unique and innovative.
However, none of that should stop you from playing the game, because it's still a great title.
The first step in playing any Civ game is to choose what kind of game you would like to play. Most of the usual options are present, including how long you want the game to go, how large the game map is, what kind of map you'd like to play on, and what difficulty the game is.
The next step is to choose your civilization. Civ V includes a plethora of civilizations, each with their own unique special abilities, units, and buildings. Most of the familiar civilizations are there, but a few new ones have been added as well, including the Siamese and Songhai. Several civilizations have been restricted to DLC (downloadable content), a move that irritates me just a bit. Everyone's jumping on the DLC bandwagon these days. As if it's not enough that most high-end games cost around 50-60 dollars, which is about the size of my monthly grocery bill.
Anyway, Civ V gameplay is very similar to that of past Civ games, except for two major changes.
First, there are city-states, little cities that exist independently of the major empires. They can do all the normal things an empire does, except expand. You can leverage influence over these city-states by paying them money or doing favors for them. In return, they'll give you some of their resources, units, or culture, depending on what kind of city-state they are.
Second, there are social policies, principles your empire can adopt that give you certain special abilities. These policies are clustered together in trees. The Tradition tree, for instance, has the policies "Aristocracy," "Oligarchy," "Legalism," "Landed Elite," and "Monarchy."
There is one other distinctive that separates Civ V from the other games. Remember meeting the leaders of the other empires? Remember how stale they were? Not anymore. Now the leaders all speak their own languages and have distinct personalities. It's pretty neat!
All in all, it's a solid game with good graphics, and it's as fun to play as Civ IV. But please, don't buy it at full price. It's not spectacular enough to deserve that much of your money.