If readers find it hard to navigate through your site, the change of gaining more readers is likely to be low. Navigation is an important feature in a blog or website because you show reader what they want faster. Even if you have the best content online, with poor navigation, it will be nothing if readers cannot find it in the quickest way possible.
Improving website navigation means visitors will find more of your content and will return for more. WpHacks.com lists 10 different ways you can improve navigation for your WordPress blogs for better usability. If you navigate to your site and find it hard to look for content, get to the homepage, etc, then follow this guide.
Full article here: http://wphacks.com/10-ways-to-improve-navigation-in-wordpress/