As you're staring at a blank canvas in your graphics program of choice, getting ready to design an image for your library's website, do you ever stop and think, "Wow, this is not what I went to school for!"?* Even if your main business is libraries, employing a few design principles will give patrons a better website experience and help "sell" library programs, online resources and collections, and digital services.
Effective visual communication is more than just following a checklist, of course, but you don't have to be an expert to use these design ideas:
Unity/Harmony: Develop a style for the website that includes a limited color palette and a selection of 2-3 versatile, easy-to-read fonts. They will be a foundation for your composition and message rather than a competing distraction from it. (They'll also be a jump start if you're uninspired or in a hurry—some of the decisions are already made.) Examples: Fayetteville Public Library, Salt Lake City Public Library.
Composition: Will you use photos, clip art, or other illustration? Use careful judgment with clip art. If the piece would work nicely in an elementary-school book report, it doesn't belong on your website. When building text into your images, look for pictures with a little space built in, or leave room in a collage of images for adding words. Blank space gives an uncluttered feeling and focuses attention on the details that matter. Examples: Brantford Public Library, Mid-Continent Public Library.
Message: Keep it short—not too many words—especially if they will appear on a small button or a slideshow image rotating every few seconds. In all writing for the web, use a tone that is fun, friendly, and professional, and be sparing in your use of all-caps and exclamation points. Examples: Multnomah County Library, New York Public Library.
* If you actually did go to art school, I hope you'll weigh in with your thoughts on design for library websites.