A majority of people on this forum knows of mods work but newbies (like me) doesn't. So i think a general FAQ about mods is welcome...

Write your questions and answers....

1) What are mods?
2) does it change the rules of your core games ie will i be able to play "normal" civilization after installing a mod ?
3) are mods usable with foreigner versions (french, spanish....)?
4) how to install mods?

1. Well, mods are modules changing the standards rules (units included)
2. Vanilla excluded, installing mods do not change your standard rules.
3. Unfortunatly, not. You need to translate some parts of your version (units folders)
4. Install them in your Scenario directory.