Is there a template “library” for use in Writer? I need a legal pleading template.
I assume you mean document templates.
In the menu
File>New>Templates choose as filter “Text documents” and “All categories”. Now you can see all document templates which are provided by LibreOffice and possibly your own.
On the website of LibreOffice
You will also find a large selection of extensions.
Otherwise, you can of course create your own document templates and save them as such.
link is broken
Now no more
Also Apache OpenOffice extensions ( https://extensions.openoffice.org/ ) can sometimes have templates that don’t appear in LibreOffice extensions