Before posting an entry in a community, you will usually need to
join it, as posting access is often granted with membership. You can then post to the community with the
web interface or a
downloaded client. There are
several reasons you may not be able to post an entry in a community.
Use the
Members security level to post so that only members of the community can see your entry.
Private or
Custom cannot be used in a community.
Web Interface
Go to the
Post an Entry page while logged in. In the
Post to menu, you can select the community to which you want to post.

Additionally, you will see a blue pencil icon on the small blue toolbar on any Community Info (http://community.livejournal.com/
communityname/profile) page where you have posting access (including communities which allow users to post entries without being a member). Clicking on that pencil icon will take you to an update page (http://www.livejournal.com/update.bml?u
sejournal=
communityname) where you can compose and post your entry to the community.
Downloaded Client
Many
downloadable clients include the ability to post entries to a community. For information on the abilities of your preferred client, consult its documentation or its menu options. After joining a community, you will need to log out and log back into your client before you can post to it.