Navigation is about helping users to move around within your web site and to other sites. If they can't easily do these things, visitors will leave your site.
Written by Philip Chalmers who is based in the Medway area of Kent, England, United Kingdom.
It's about helping visitors to find their way around:
Visitors will leave your site if:
They will learn to avoid your site if they can't back out to another site.
They will resent it if you box them in.
They will get bored with your site if it doesn't lead to other interesting
sites.
You can't hope to cover everything.