WP PageNavi is an excellent way to manage masses of content into a user-friendly navigation. Instead of having the standard WordPress next post and previous post it has a list of the page numbers or posts. This enables the user to navigate there way through the website with complete ease and not having to click through post after post to get to the article they are after.
This plugin gets a 5 star rating on the WordPress plugin database and the installation is very easy, just add it to your plugins folder and activate in the admin dashboard. Also if you know your css you can easily customize the plugin by editing pagenavi-css.css in WP-Admin-Options-PageNavi. For a demo of this plugin visit http://www.lesterchan.net/wordpress/ and scroll to the bottom of the page.