This course is an introduction to CSS and what to do with it. 
HTML and CSS simply explained in Pictures. The course comes in pdf format and will be downloaded to your computer.
joomla
Joomla! is a great CMS for building and maintaining websites. This is the official Joomla User Manual. It will be downloaded as a pdf to your computer.

nvu
How to build websites with NVU.

WordPress is a Content Management System and blogging tool. A blog (web-log) is an online journal, diary or commentary, presented as a website. Generally, one or more contributors (bloggers) add new content to the top of the website on a semi-regular basis.
This course is covering all about the CMS Plone
An introduction to SEO by Derek Jansen.
60 online tutorials