Your website should be treated like a working document - forever requiring fine tuning and adjustment.Never, never have a blank page on your website, and never, never have a page that says 'Under Construction'. You would be better off having just one website page with all your contact information on it, than having lots of incomplete pages.
Keeping your website content up to date can take up a lot of time, especially when you are busy trying to run your business as well. However, in order to encourage your website visitors to keep returning to your site, you need to make sure your content is always fresh and relevant.
Make updating your website part of your regular schedule. Put it on your calendar. If you can, learn how to update your website yourself, or find someone reliable to do it for you.
I love this analogy, which I came across recently: "In today's world, websites are your shop window... think about this - if your store front never changes then what kind of impression are you sending out to the world?" Certainly something to ponder...