need plugin so readers will join my facebook group page

is there a plug in that simply puts a facebook icon on my home page, and perhaps says “join our facebook group page” or something similar, and then clicking on it will take readers to my already existing facebook group page? (i suppose for people who are not yet facebook members, i want it to take them to a place where they can a) see my group page and b) join facebook, so they CAN join my group page. thanks in advance …