I thought I'd help out, as this seems to be a common problem with very little complete advice, and a lot of bad advice. The Ubuntu docs only get Joomla installed, and don't go as far as enabling SEF URLs. I plan to put this into the docs pages somewhere soon.
Problem: For some people they can rename their htaccess file and click 3 radio buttons to get SEO options working.
For others... It fails. You've made an Ubuntu or WAMP server but the CMS website it's hosting can't use SEF URLs. You've followed the documentation for Joomla (or any CMS) to create SEF URLs, but it's broke. You can even get it working on a a site hosted by godaddy.com or hostgator.com - Perhaps you don't care about SEF URLs and you are trying to use the features of htaccess, yet it's broke.
In the example below I was using Ubuntu and the Joomla CMS installed into a folder called "joomla" with the sample content, and all 3 SEO settings=yes in the global configuration. XAMPP servers seem to have mod_rewwrite working with the default installer. WAMP needs the same fixes as Ubuntu.
errors observed in your web browser:
The server encountered an internal error or misconfiguration and was unable to complete your request
The requested URL /joomla/example-pages.html was not found on this server
steps for ubuntu server:
1)go to the ubuntu command line
2)type the command: sudo gedit /etc/apache2/sites-available/default
notes: This is the default server configuration file using ubutu server
3) Make 2 changes to the code, see default code below
original: AllowOverride None
new: AllowOverride All
========segment of default code ===================
Options Indexes FollowSymLinks MultiViews
allow from all
4) Save and close gedit
5) type the command: sudo a2enmod rewrite
notes: the ApacheENableModule tool (a2enmod) now enables the "rewrite" module for good. The next time you reboot, the module loads automatically
6) type this command: sudo /etc/init.d/apache2 restart
notes: this restarts the apache2 web server without rebooting your pc
7) test that .htaccess files are being loaded properly by apache
type the command: sudo mkdir /var/www/foofolder
type the command: sudo gedit /var/www/foofolder/.htaccess
in the file add these 2 lines below
Redirect /foofolder/foo.html http://www.google.com
Save and close gedit
Open a browser and test your server URL by adding foofolder/foo.htm
example url: localhost/foofolder/foo.html
result, you should see google
9) Follow the steps for SEF Urls in your docs for your CMS website
SEF = Search Engine Friendly
(the opposite of long URL's with querry strings)
10) For the Joomla CMS you would rename the default file
and set all 3 SEO settings to "yes" in the Joomla back end, global configuration
ubuntu command line: sudo mv /var/www/joomla/htaccess.txt /var/www/joomla/.htaccess
Steps for a Wamp Server
use notepad to edit the file
Your folder may have a different apache version
search for the text "rewrite"
remove the pound symbol # - at the start of that line of text
search for the text "None"
change it to "All" in both places as noted in step 3 above
save and exit notepad
click start, run, cmd.exe
type the commands
rename htaccess.txt .htaccess
use the mouse to click the wamp menu stop all, then start all