I've established a Facebook page for our company, and we do have some fans. I've followed the pattern of some very successful companies in the design of the site - I've included and update our news articles regularly and have space for reviews / notes. I have also tied the facebook account to our YouTube account (we upload videos of many of our products to YouTube) - I think this adds some interest to the page.

What can I do to take the Facebook page to the next level, i.e. increase the number of visitors and get traffic to our website?

Facebook marketing is mostly limited by the size of your network of friends. To make this more effective, one of the only things you can do is build more contacts, especially within your industry. To help build more contacts, you could try joining related groups.

you should put a button on your website "find us on facebook"
You could join groups on facebook to promote your facebook page.
You can just promote it the same way you would promote your website. It is a webpage like another. It has content, links, articles etc...