That should be covered in the documentation for the extension:

• SiteLauncher :: Add-ons for Firefox
  https://addons.mozilla.org/en-US/firefox/addon/sitelauncher/

Firefox has keyword shortcuts, which can provide you far more flexibility in bringing up sites with easy to use and remember shortcuts, because you make up the shortcut name, So if your bank is named "First National Bank of Cincinnati" you might use a shortcut like FNBC capitalization of a shortcut is optional the case of a keyword shortcut is ignored.

For more information on keyword shortcuts see

• Firefox Keyword Shortcuts
  http://dmcritchie.mvps.org/firefox/kws.htm

In order to use keyword shortcuts without a lot of hassle, I would recommend installing "Add Bookmark Here2" extension, and if you don't use tags to clean up the bookmark dialog by removing tags from the dialog, and of course including keyword in the dialog. You will see what you need for the extension in the Keyword Shortcuts link.

I would personally dump the Site Launcher extension as too limited and too difficult to maintain. Three other strikes against it, is it is a very large extension, which does very little, the author is asking for money, and I see several problems listed in reviews, and the fact that it has its own privacy policy and continue to download link should raise eyebrows.

I am a newcomer to firefox and when it comes to computers I am a long way from being an expert, and if I am honest, some of the things you wrote, I did not understand. All I want is to be able to go to sites of my choosing quickly and easily, and site launcher seems to fit the bill. If Icould only get rid of the rubbish and install my own sites. I have looked & looked& looked, and nowhere can I find anything that tells me how to do this.

                                                     regards,        terry123