Different types of menus
The best type of menu for your website will be determined by the amount of content that the site will contain. A clear, easy to use menu system should ensure that the user is never more than a couple of clicks away from anywhere on the site.
For smaller sites a top menu with four to six buttons will probably be the simplest was to provide clear site navigation,, but if more pages are required then a combination of top and side navigation bars perhaps with tabbed sub menus may be more appropriate.
Whatever combination you decide on there are a wide variety of styles from simple link text to bold coloured buttons, rollover menus which expand to give further options on mouse over, or images combined with text to give a more intuitive feel to the navigation.
Examples of various approaches to website navigation
Classic centre column design with rollover top and side menus which drop down or fly out to the side when the mouse is held over to give multiple options, a great solution to multi page websites.
Simplified version of the above, with top and side menu bars which don't expand, you could choose to have just the top or just the sidebar, or perhaps if there is one particular page on a website which would be better broken up in to multiple categories, a combination of the two.
A simple, striking, easy to use layout which emphasises the image content of the design rather than the text. A great choice for a website that doesn't need many pages but still makes a bold impression.
An uncluttered single column design which doesn't distract from the text so a good choice where a large amount of text is required. Simple navigation doesn't draw attention from the content but the rollover menu allows for a powerful navigation system.
A nice, simple, powerful design with equal precedence given to both text and images, also with an interesting variation on the standard navigation system using featureboxes containing text and images to add to the visual appeal of the web page and the navigation.
A three column design which goes against the grain slightly as I personally prefer a simple layout, but there is great scope with this layout to provide links to a great deal of information from the homepage.
This example shows a tabbed menu which could be used as the main navigation for the website or to expand a particular section of a website, to organize multiple pages within a particular category without making the main site navigation too complicated.