WordPress.org

1. Upload calais_archive_tagger.php and opencalais.php to the /wp-contents/plugins directory
2. Activate the plugin through the 'Plugins' menu in WordPress
3. Add your Open Calais API key through the 'Calais Archive Tagger' sub-page of the 'Plugins' menu
4. Click the 'Start Tagging' link on the 'Calais Archive Tagger' sub-page of the 'Plugins' menu

To obtan a Calais API key:

1. Go to the Open Calais website at http://opencalais.com/
2. Click "Register" at the top of the page and create an account
3. Request an API key at http://developer.opencalais.com/apps/register

You should receive the key immediately.