Hi Moe,
No it doesn't show posts & content on your FB wall, so your posts won't be on other people's newsfeed.
It will only show as one of your 'likes' if you click on the FB link (hence liking the forum as a whole) that would show up on other people's newsfeed as you liking this Fibromyalgia Support Group and Forum.
Even though I like the forum so far, I don't want it on my FB page, therefore not clicked on it.
Hope that's not confusing x