That having been said, I do have relevant input myself.
Do not try to make a graphically intensive site. Web design today must be focused on swift functionality. You will lose visitors to your site if it does not complete loading within 20 seconds. Preloading all the images for the site makes this worse.
On the other side, preloading is only viable for dial-up users, or broadband users with many concurrent downloads.
You want to keep visitors on your site, keep it clean and simple. Look at my site,
http://www.mjhnosekai.com/ , there are but a few images. The background image, the "scanline" effect, is only 2 pixels in size. Not even a few bytes. The banner is larger, but my site doesn't hinge on its visibility. Little XHTML 1.1 Valid, and CSS 2 Valid icons on the lower right are small, but again, not majorly important. Images I use for my articles, again, not entirely important, just focus to add an effect. One can browse my site with images off, and it'll still be rendered pretty effectively.