The screen above is what you are presented with on first loading the XML site maps module from the Other tab.
The screen only has three settings that we need to consider:
Create a Google Site map – If you want to have a Google Site map for your Web site make sure there is a check mark in the Create a Google Site map checkbox. Unchecking this checkbox will ensure no XML site map is produced for this Web site.
Filename – The Google site map is an xml file and so you must choose a filename for it. You do this by typing the filename into the box labeled ‘Google Site map’.
Note: When entering a filename, be sure to end your file name with the file extension: .xml
Include Robots.txt link option – Checking this option inserts a link, in your robots.txt file, pointing the search engine spiders to the XML site map. This is a double-measures approach of ensuring that Google finds its way to the indexing 'sweet-spot' of your site. Unchecking the check box will remove the entry in the robots.txt file.
Once you have made the three simple choices above, click the button to move onto the second tab.