When I select Writer/Help/LibreOffice Help, I get a Help menu description at Help - LibreOffice Help. This describes the menu but I don’t find any help pages. I’m on 4.4.5.2/Windows.
[edit: added lo4 + win tags]
Use the search bar top right.
I think it is best download and install the help pack for your UserInterface language.
You can find all available languages for all versions here:
http://downloadarchive.documentfoundation.org/libreoffice/old/?C=M;O=D