It's easier than you think - just 4 easy steps:
Step 1. go to developers.facebook.com/docs/reference/plugins/comments/ and choose the options that you want for your new comment section.
Step 2. You will be prompted to login to facebook to get an application ID that is specific to that page URL.
Step 3. Once you get to the page where it generates the APP ID you can go back to the comment generator and do it again - it will give you the HTML code with your new ID embedded.
Step 4. Cut and paste the HTML code into the correct portion of your site.
There are also instructions about moderation of comments
This is a link to the moderators comment tool developers.facebook.com/tools/comments.
- and facebook is touting the fact that all of its users are genuine so you won't get as much spam and crud in your comments (because the comment appear on the users facebook page :)
Check out what this looks like by going to my new facebook comments section on my homepage - tobyonline.co.uk
This follows hot on the heels from my very recent post of retrofitting comments to your website using Disqus ...now your have another options - cool.