Dark text on a light colored background is your safest bet. Backgrounds with patterns or texture are risky. Remember that all eyes are not created equal. What looks fine to you may be almost painful for another reader. Perhaps the greatest assault on web site readability is animation.
Animated images exist to draw attention to themselves.
The more information that your site contains, the more important it is to provide an understandable navigation scheme. Consistency throughout the site also speeds the loading of pages. If most of your pages use the same background and icons, the visitor's browser will have an easier time presenting each new page. Each type of structure has its advantages, and can be effective if it is well done and appropriate for the material.