Facebook like plugin
For example, your website is awesomewebsite.com and your facebook page ishttp://facebook.com/awesomewebsite...
So you go to the page that generates a "Like" button for you. And it asks you for a URL to your website. Sethttp://facebook.com/awesomewebsite... as the URL and then paste the code on your website.
This will work.
Disregard the comment above, it uses FBML (I think) and will stop working this month. I don't think citytech got your question right.