more tips soon...
   
Introduction
simplicity
lead in to page
space
don't clutter
page sizing
use proportions
overkilled effects
wise effects
colour
framing
backgrounds
navigation
fonts
font ideas
 
    
Choose a background that doesn't dominate the page or make it hard to read. It should add to your theme. Your imagery and text should sit easily over it without causing eyestrain. Avoid black if possible, as it can be hard to do well.
The web is full of free backgrounds, but other sources, such as scanned images (wallpaper?) can work well.