In
Civilization: Revolution, you are building your own empire from one city (possibly more if you choose a scenario). When you start a new game, you're given the choice of 16 different nations. Each one has their own advantages, so it's really a matter of personal preference as to which one you play as. You'll probably want to test all of them out eventually, especially if you want all the achievements.
After you choose your nationality and difficulty level, you'll be started out in a random location with the rest of the board unknown. From here, it is your choice as to how to proceed. Your city can only build one thing at a time, so you have to balance between building troops to explore the world and buildings to help your city grow. Granted, you won't have the building ability until you discover some technologies. You learn those from science output.
There are several (8) types of terrain that you can build on. Your city will use the terrain around it for production. You can see what each square is producing from inside the city screen. If you want, you can micromanage all your workers to have the city produce whatever you want. At first, you'll probably want to just leave it balanced and let the computer control all that, at least until you know what you want.
There are several different things you'll encounter in your explorations, other than the other civilizations. The first thing you'll probably run into is the friendly villages. They will give you things like a caravan, or perhaps share knowledge, or maybe even join your civilization. Unlike some of the older games, these villages are set from the onset as to what they give you, so you can't save the game and then reload to get something else if you don't like what they give you. Once you encounter them, they'll probably tell you of a barbarian village nearby that has been harassing them. You can go clear out the barbarians to get them out of your way and possibly get gold or even convince them to join you. If you're playing as the Mongols, barbarian villages will always join you after you've beaten them, which will expand your city count very quickly. The one other notable thing I found when exploring was Atlantis. It is considered one of the 6 artifacts in the game. Unfortunately I couldn't keep it as a city, but it did give me the knowledge of several technologies (4 if I remember right) instantly.
There are four different ways to win the game. You can choose to take over all the other civilizations, thus winning in domination. You can choose a cultural victory if you have enough Great Persons and build the United Nations. An economic victory requires you to have 20,000 gold in your treasury and then build the World Bank. My personal favorite (and longest) is the technological victory. To win with it, you have to learn all the technologies and land a space ship on Alpha Centauri. After you do win, you'll be able to see your rank, a histograph, final scores, game stats and trophy room.