From SK's Wiki
- Download WorldGuard and WorldEdit (WorldEdit is required).
- In the folder with craftbukkit.jar, make a "plugins" folder if it's missing.
- Copy both WorldEdit.jar and WorldGuard.jar into "plugins".
- Restart the server.
Default configuration files will be created in plugins/WorldGuard/ when WorldGuard (and the server) is first started.
- Edit the file config.yml inside the folder above (How do I do this?) and change the configuration.
- Each world also has its own configuration so you can override settings for each world. See the configuration page linked above for more information about that.
- Set up permissions or use worldguard.* for all permissions (What are these?).
/wg reloadin game to reload the configuration (and permissions).