A friend once recommended me this game and I was a bit weary: I had never played a 'Civilization' (or 'Civ', for short) game and starting on the 4th didn't sound like a good idea.
So I bought the game and tried it out. It is very easy to install and will work with most modern computers. When entering the game, first-time players can play the tutorial, which explains some of the main concepts of the game. I found it incredibly informative and I found it easy to grasp.
The graphics are beautiful. The level of detail in items such as cities, terrain and units are amazing. However, if you don't have a good graphics card for your computer, then you may experience some slowness.
Basically, in Civ 4 you start out as a small tribesman and expand your empire by building cities and conquering players. The turn-based quality allows multiplay that is not doen over the internet, which I found immensely useful. Players can have the choice from starting at 3000BC or throughout later periods of time, allowing for full customization. As time goes by, new technologies, units etc. become available to the player.
Occasionally I found the gameplay a little confusing, but with frequent use you become well aquainted with the layout. I would definitely recommend playing the tutorial, especially if you are a new player.
This strategy game is one of my current favourites and I would recommend it to all strategy game lovers out there, looking for something new.