Here are some tutorials on the net about how to create various menus
Horizontal Top Nav Menu
- Sliding Door Technique for horizontal tabs by Douglas Bowman who gave this excellent talk on CSS techniques.
- Graphical Horizontal Menu - with hover effect using unordered list
Vertical Side Menu
- Taming an Unordered List to create Vertical menu. To avoid using tables for menus, you typically use unordered lists.
- Uberlink CSS List Menu - includes hover effect and highlight selection. It uses the Uberlink javascript script to highlight the selected menu based on the URL.
Drop Down Menus
- Digg-style Drop Down menu - uses ul and li's in conjunction with Javascript