One of the most important rules of web design is that your site should be easy to read. This is determined by a number of factors:
There should be a sufficient amount of contrast between your text and background
You should make appropriate use of the "white space" of your page. This is the empty space between your text, and it can act to both guide your visitor's eyes through the page and allow your visitor to rest between sections
The use of eye-catching backgrounds should be avoided, since these act to draw the visitor's attention away from the text
The font style should be chosen carefully. Serif (e.g. Times New Roman) and san-serif (e.g. Arial) fonts are popular choices that are easy to read. Overuse of italics, CAPITALS, and decorative scripts should be avoided
Font sizes less than 9 pt (size="1" in HTML) should not be used. It is also worth remembering that fonts appear smaller on Macintosh systems than on Window systems, owing to a different in screen resolution
Break large documents into "easy-to-digest" chunks or provide a PDF version of the document for download