There is also LyX. It is a document processor, so it tends to help any sort of focused writing (however, keep in mind that I use it for reports and articles, not prose).
As long as you keep yourself from trying fancy stuff that would require Latex knowledge (LyX calls that "evil red text"), it just works and it will typeset her books to PDF with a single click.
It is damn easy to install (even in Windows) nowadays.
The spellchecker, OTOH, is not nearly as advanced as OOO's.