You have to register for a Bravenet account first.

check out quackit.com for codes since this is suppose to be a helping center not everyone here is not eager to help...
Good Luck

You get the code for the tell-a-friend (or any other service) when you register for that (free). You customize it, so it matches your site's look, and then copy and paste the code into your website wherever you want it to appear on the page.
Bravenet provides you with the instructions to help you with this, and they even have a page available for extra help.
Good luck!