Hi,

By default, documents/pages (from content tree from CMS DESK) of type CMS.MenuItem are displayed in menu navigation web parts. So, you can simply create documents of type CMS.MenuItem and these items should be displayed in your menu navigation web part if this web part is configured correctly. If you want to display documents of other types in your web part, you need to specify the document type in “Document types” property of your web part. Menu navigation web parts will automatically create links to these pages. Each menu navigation web part can be styled according your needs using CSS styles. Example of such modification can be found in following documentation:

http://devnet.kentico.com/docs/controls/cmslistmenu.htm

Best Regards,
Miroslav Remias.