To add links to your group's social profiles to your site, just edit Site Settings and on click the "Social" tab.

Add the info for each of your group's social profiles and click the "Update Settings" button:

Note that some fields ask for the full URL and others just for the username - sometimes having the username lets us create a deeper integration on your site (like adding Twitter/Facebook sharing).

As soon as you save your links, you'll see icons on your site for each social site you've added: