Book excerpt: Every graduate student, postdoc and scientist knows that images and illustrations can make or break their lecture, poster presentation, and journal or book article. Graphics software and laser printers have placed professional-quality graphics within the reach of everyone. But in the end, whether your audience sees clear, understandable images or not depends on whether you followed the principles presented here. Learn the strengths and weaknesses of different forms of visual presentations. Understand when to use a figure, and how much information can be represented in one. See examples of bad, good, and better graphs and tables. The author also presents information on presenting DNA sequences, protein structures, and other molecular graphics. '