If you need a simple plugin to navigate through your posts by first letter use this plugin.
You can either install it automatically from the WordPress admin, or do it manually:
- Unzip the archive and put the
wp-alphabetic-navigation folder into your plugins folder (/wp-content/plugins/).
- Activate the plugin from the Plugins menu.
Usage
You can configure the WP Alphabetic Navigation plugin from Options section.
If you need custom layout you can put <?php show_aphabet(); ?> in the proper
place of your theme. But first you should change layout to custom
WP Alphabetic Navigation on options page