If you go to the Userinfo page of the community, you know where they have the little buttons at the top? Um, there's a heart so you can add stuff to memories, and there's also a button that let's you friend the community. Well, there's a button that has a picture of a pencil on it, and that's the one you click to post stuff to a commmunity. You also have to be a member of the community, and the link for that is also at the top of the Userinfo page.

Heh, sorry if that didn't make much sense! I hope you can figure it out. ^.^ Let me know if I need to be more specific.