I know that there has been talk of a shared journal FAQ, though I don't know what's happening to it.
But, a lot of time users want to post in multiple journals without logging out of them, and the answer inst always a shared journal.
What do you think about a "How can I post in multiple journals without logging in and out" (needs a better name) FAQ?
It would include information or clients that can be logged in to multiple accounts, shared journals, and communities.
It wouldn't need a lot of information.
Just a basic thing saying "some clients can do Foo" and perhaps a couple links to journals/journal communities (or not).
A link to the shared journal FAQ, but also stating within this FAQ that you need to first convert a journal to a community, and a link to the "how do i create a community" FAQ with a short explanation that explains that you can not grant members posting rights, so they can read protected entries and comment, but not post.
On a completely unrelated note, I posted a first draft of the change for FAQ 142 here.