Template editing docs:

http://localwiki.readthedocs.org/en/latest/customizing.html

https://docs.djangoproject.com/en/dev/topics/templates/

Editing HTML templates in:

/usr/share/localwiki/templates/site/

Local CSS file:

/usr/share/localwiki/static/css/renosparkswiki.css

Header and other images:

/usr/share/localwiki/static/theme/img/