There is a a good FAQ starting at
https://wiki.documentfoundation.org/Faq
It was originally created by the French Team, in French. The
translations into English are continuing, but most of it is complete.
One major use of the FAQs is when answering questions from users:
giving a link to the relevant FAQ page.
Many of the FAQs would benefit from people improving the English and,
where necessary, replacing the French screen captures with the
equivalent English ones.
Many of you on this list have expressed interest in helping the user
documentation effort by proofreading. Working on the FAQs would be a
great way to contribute, and has the advantage that they are "bite
sized" and thus can be done when you have a few minutes to spare.
And if, while doing that, you spot something particularly interesting
(for example, the sort of thing that makes you say, "Oh, I didn't know
you could do *that* using LibreOffice!"), then bring it to our
attention on the list and we'll see about writing a blog post on the
topic.
--Jean