If you need support from Yola please contact us via firstname.lastname@example.org or make use of our live chat service! We are working on a new approach to community-based support and during this transition period we are not adding any new threads to this forum. Many thanks to everyone who has participated over the years and we look forward to unveiling a new peer-to-peer support system soon!
We do have this logged as a feature request and we know it would add value to those of our members building sites for others. We have investigated this and other membership features in the past and will continue to consider the value it might provide to members going forward.
The sitebuilder automatically generates a sitemap for each site you create and it has been optimised for Google and other main search engines being an XML file. You can actually view it by going to your browser and typing your website address such: mywebsite.com/sitemap.xml.
You don't have to do anything to facilitate the generation. The submission of the map is discussed in the tutorial Tutorial: Google Webmaster Tools (Step 2 has some additional info on the sitemap specifically)