Maybe I don't want to be surprised by background music when I'm surfing at midnight. Bandwidth, browsers, and computers vary. For overall user friendliness, as well as the reasons discussed in topics 8 and 9, I limit the size of my graphics to no more than 50 kb, and try to keep the total size of my page to less that 100 kbs. I use only browser friendly colors, and test my pages for less than a minute download times. Animations, blinking text, java, and frames can do far more to distract from your message than add to it.
Web design is first content and functionality.
Design and outline your site based on content and functionality, then decide how the sizzle can be added. While the technology continues to change and advance before our eyes, the concept of planning hasn't really changed all that much since. Planning begins before you get to the computer. Draw a basic layout on paper. Save stories as text only first.