The navigation menu should help visitors find the product they are looking for. It has to give them an overview of the available range of products.
Make your primary navigation prominent and simple with 5-7 choices
When naming your categories, use words that your users are familiar with instead of inventing creative category names
Make sure the top landing pages of your site are accessible from the main navigation
Use top or left navigation based on the nature of your website
Show the navigation menu consistently throughout the site except on the checkout page
Indicate where the user is by highlighting the link in the navigation menu.