We are living in an age of graphics. More people watch television than read books. Since people are oriented toward the visual, we can use this to our advantage to make them want to read.
Readers use photos and graphic images as entry points.
But pictures generally say it first. All art used must be of high quality. It must be simple, well done and get to the point quickly. Superfluous art can be worse than no art at all and can distract the reader and dominate the layout. A carefully selected picture can create a mood more effectively than perhaps the legendary 1,000 words.