Top, left, bottom, different for each page, which is best?  Well, it depends on your website and its content.

Most people are used to left navigation but that doesn’t mean it’s ideal for all websites.

Before you decide, consider the types of products you have, the number of pages and categories.  For websites with a static number of pages, such as a small business informational website, top navigation is most appropriate.  Whereas with an ecommerce site left side navigation is better because you can expand your list without impacting the design of the page.

That said, remember to always include basic navigation at the bottom of every page.