It has been said that the web is a "wild west." What they mean by this is that there are very few rules and those few rules are routinely thrown out and replaced with different ones. There is not one way to make an author website, but there are some things that you should have.
About Page
If people are coming to your website, they are coming to find out about you or your works. Probably both. Have fun with your about page. Make it sound like you. If you are a physics loving, technology devouring, super genius with the interpersonal skills equal to a self-checkout machine, that's okay. And if you are the kind of person who can invite your closest friends over for a way cool party complete with movie, food, and lots of laughter. And throw all that together in less than an hour from initial idea to FUN. That's okay, too. Make your page sound like you. There will be people who will connect.
Contact Page
Make sure there is a way for people to contact you. Especially if you have published anything: articles, news stories, short stories, books, anything.
Blog
You need a place on your site that is easy to update with news or thoughts or articles. This makes it easy to put some content on your site and for others to follow you.
Works and Works In Progress
You should mention any published works. Include pictures and summary text. If it can be purchased online make sure to include a link so people can buy it. If it has an ISBN make sure to include it. By using the ISBN a person or company can easily find your book in almost any system that catalogues books: online stores, offline stores, libraries, etc.
You can also list your works in progress. Some people like to include bar graphs showing their progress. You can include a quick blurb about the story or just the genre information. Whatever you think people will enjoy.
There is still a debate if you should post any of the actual text from your works. To play it safe, don't post anything until your publisher (or future publisher) tells you it's okay. But this is one of those "rules" that is in flux.
Lies—Bald-faced Lies. Not!
Whatever you do, don't misrepresent yourself. If you only have one book published, say that. If you don't have any that's fine, too. Don't try to make yourself out to be more or less than who you are.
Advertising
Depending on how much traffic you get it may be worth your time to put advertising on your site. Since this is a more advanced topic, we won't cover it in this workshop.