Remember the audience for whom you are writing. When you make a reference, qualify it with a clue to allow some people to skip it. Choose an appropriate size for your document. Long documents will take longer to transfer and are difficult for a reader to scroll through. Be careful about introducing too much graphic material into the your documents.
Larger graphics tend to slow down significantly the time for a page to load.
If you have a lot of large graphics, it is advisable to link them to your documents and give a warning that the site they are about to link to will take some time to load. If you decide to use a different body background for your pages, make sure the background does not distract from the text and graphics found on the pages. The background could also hide the text and make it difficult to read. Color should also be a factor. Unless you are trying to grab people with bright colors, it is preferable to stick with pastel colors.