Hi andrewredblu,
thanks for using MH Newsdesk lite.
When it comes to CSS modifications, you can always use tools like Firebug to inspect the elements on your website, see how the CSS has been applied and then use this information to add your own custom CSS code, for example:
.main-nav ul ul li { width: 200px; }
To add custom CSS code to your website, you can either make use of plugins like Simple Custom CSS or create a custom child theme.