I don't care if you listen to me about any other tips listed on this website, but if you won't listen to this tip, then you're truly doing yourself a disservice by even having a website.
KEEP YOUR WEBSITE UP TO DATE! - I'm not screaming, I'm just trying to get a message across. :)
This is the biggest mistake actors make and everybody's losing out because of it. If you don't add your newest contact information, people won't be able to contact you - that's simple enough, but... if you don't add new content to the website, people will assume that the website is old and no longer active.
There's ton of situations where actors start a blog in 2013, post two blogs and give up on writing anymore. If you went to a website and saw that the last post was made 3 or 4 years ago, what would you think?
What's worse is when an actively working actor doesn't add new acting credits to the website. This is just wrong. If you're listing credits on your acting website and your last credit is from 2008, I will assume that you're no longer an actor. I wouldn't know if you're retired or decided to become a director instead, or if you're even alive. It makes no difference to me that the domain name is still active. If the content is outdated, I will think that you're out of the game.
Sometimes small things like having a date on your copyright say: "2008 - 2011" might be an indicator to others that you're not even looking at your own website.
To solve this at IADB, we've built algorithms to keep your information up to date, but other companies won't do it for you. You have to stay on top of your own website. If you don't, you might as well not have a website at all.
Final hint. If you're not planning on updating your blog, remove it from your website. If you're not planning on adding each new credit, remove it from your website. Sometimes it's better to just have your photo and a contact form than to have information that is just not up to date.