As a developer, I'm working on a site that has more than 7 top level menu items horizontally and 2 of those top level items contain more than 15 sub-categories. It's quite congested. This is an ultra competative travel destination site so SEO & conversion optimization is really important.
No doubt I can break the items further into other sub-categories but I'm wondering if I can create a secondary menu as a side bar or tabs or something. Is there a resource out there that you may know about that can help me understand best practices for layout of large menus and how it affects user browsing patterns?
Any experts with some suggested dos and dont's from a marketing perspective regarding menu layout?