When you want to post content that links back to your site—say, information on a particular product you want to draw attention to or a blog post you'd like to promote—don't just post it on your own fan page. Use other, already established pages to reach untapped and potentially larger audiences.
For example, suppose your site sells diet supplements, and you've just written a blog post called “5 Secrets for Staying Fit.” Of course, you'll want to put a link to the post on your own Facebook Fan page—but why stop there? In the search field at the top of Facebook, look for other fan pages having to do with dieting, weight loss, fitness, etc. Yes, you'll find a bunch run by other companies who probably won't let you post on their wall, other than to comment on things that they've written. But you're also likely to find a lot of more generic pages, like “I'm Healthy and I Know It,” that are more like open forums for people to share info on a certain topic. Usually, these pages will allow anyone to post content; feel free to add the link to your post to as many of these pages as you can find! (Do it over a period of time, though; Facebook may think you're spamming if you place the same link on too many pages too quickly.)