User Experience comprises many aspects of a website, including the navigation, the content, the design, and the staying power. The idea behind web usability & user experience design is to make sure people don’t have to *think* very much to use your site — it should be intuitive, and not get in the way of the goal behind the site (eg: sell a book, have people contact you, etc..).  While there are some blanket rules for web usability (from Wikipedia)…

1. Present information to your users in a clear and concise way,
2. Remove any ambiguity regarding the consequences of an action e.g. clicking on delete/remove/purchase,
3. Organize your content so that it’s obvious how to use the site

…there are also specific usability & user experience guidelines for each web niche, including author and book websites.  Having designed many author and book websites, and tracked analytics to determine design success, here are some guidelines I’ve come up with that help create a great user experience for author and book website: 

• Be sure the site visitor knows who you are.  Even if your website is designed to mimic the universe created by your story, people still want to know about the person behind it.  It’s a way of building trust with your audience, and a way for them to further invest in what you’re doing.  For example, Chelsea Cain’s website does a GREAT job reinforcing her genre through the design of her site, while also celebrating her as the author.
• Write the text for the site in a similar tone to your book.   Did you write a self-help book that offers advice in the first person?   Or a romance novel filled with beautiful, lengthy descriptions?   You want a continuity of experience between your presence on the web, and your presence within your book(s).  Jacqueline Mallorca, The Gluten Free Expert, does a great job writing her website content in the same friendly, approachable manner as her cookbooks.
• Design the site as an extension of the brand you have built through your cover art.  You don’t need to reinvent the wheel when it comes to your site navigation or layout, but make sure the design of your website enhances your book cover(s) without overtaking it, and has the same attention to detail.  Whether your cover design is clean and modern, or moody and painterly – you want the experience with your site to envelop the user with that same feeling.  It’ll help the experience on the web *and* brand recognition.  Here’s a great example.
• Say what you mean & make your links explicit.  This is not a time to be vague and mysterious – if you’re offering a top-ten tips list based on advice in your book, say something like “Discover my Top Ten Tips for ________” and make the entire thing a link.  If users know what to expect, they’re more likely to click the link – as opposed to a link that says, “What are you doing to help _______?”  This idea can be used in lists, on buttons, within the text, etc…    Don’t hide high-value things away on other pages of the site without clearly telling your user about them on the Home page.  Here’s an example that highlights the excerpt, an interactive timeline, and the author’s social media links in an unambiguous way.
• Give people an easy way to get in touch and/or participate, including (and especially) the press.  Everyone hates a website where you have to hunt around for a way to get in contact (hello cell phone companies!), but when you’re marketing something it’s even more important that people find it easy to ask questions and get more information.  You don’t have to give our your personal email address – maybe you have a publicist, or you create a web form, or an 800 number people can use to leave a voicemail…  there are many options, but you don’t want to cut yourself off when opportunity comes knocking.  In addition, you want to provide the press with the majority of what they need right on the site – this includes a press release for the book launch, whether you’re available for interviews, some see interview questions, and an author bio.  Make it as easy as possible for people to promote you!  Malcolm Gladwell’s site doesn’t do the best job of titling the page, but once you’re there it provides all the info people might need.
• Offer more than just the basics.  Whether you wrote a novel, a how-to guide, or a cookbook, there will be something else you can add to bring your book to life.  How about a free recipe?  Or a worksheet for getting something accomplished?  Or a snippet of extra content?   Just like everyone loves the Special Features on a DVD, your website is an opportunity to enrich the experience for your audience, and keep them wanting more.  Your value add doesn’t have to be a huge investment, but you can be quite creative with it.  Dr. John Telford’s site about his memoir offers images of the events covered in the book, an interactive timeline of major events in his life, and a video of him talking about his experiences.