There are no rules with web development but there certainly are some principles that most sites should follow. Last week I discussed the importance of capturing your visitor's attention quickly. Let's follow on from that by discussing your site navigation.
Keep your top level navigation to 8 or less options - more than that may leave your visitor wondering where to go.
Restrict your navigation to 3 levels deep - again this results in a logical click-through sequence. If you have to continually click to find something, your visitor will go elsewhere.
Use logical navigation text - if it is services - call it that rather than something obscure like how we can help.
Use keywords in your navigation text - if this doesn't break the above rule.