I came across a nice and practical configuration list of things you can do to increase search engine rankings for Joomla websites.

Here are some Joomla SEO tips:

1. Turn On Joomla Search Engine Friendly URLS (SEF)
2. Install The SEF Component (Sh404, JoomSEF)
3. Make Joomla URLS SEO Friendly
4. Good Page Titles & Clean URLs in Joomla (include keywords where you can)
5. Insert H1 Tags In the Joomla
6. Use a good sitemap component (xMap)

Also worth checking out the post “Top 15 SEO Extensions For Your Joomla CMS” by WebDesignBooth.