With the new 2.3 release WordPress supports a native tagging system for posts. This plugin allows you to insert tags to pages too and not only to posts.
When you activate the plugin it just works adding the tags field to the page editing form. Fill it with the tags you want in each page.
To view the tags in your blog you have to add the WordPress function to your themes, please refer to the documentation page for more information (https://codex.wordpress.org/Template_Tags/the_tags).
You could find every informations here and much more at http://www.michelem.org/wordpress-plugin-tags4page/
- Download the plugin tags4page
- uncompress it with your prefered unzip/untar program or use the command line: tar xzvf tags4page.tar.gz
- copy the file tags4page.php in your plugins directory at your wordpress blog (/wp-content/plugins)
- activate the tags4page WordPress plugin at your Plugins admin page