There are many ways that can be used to submit sitemap to search engines.
Lets discuss approaches
1. Put sitemap.xml in public folder and you are done.
Crawlers will find it through url
2. There are many online sites which generates sitemaps for you.
3. Open following urls in browser. Be sure to add xml sitemap path for your site.
a. Google submit
c. Ask Submit
d. Webmaster submit
5. Best practices in rails to submit sitemap is scheduled task (cron job).
Write a rake task that will generate sitemap in rails public folder and
will submit sitemap.xml file to search engines. ( as mentioned above.)
Got easy 🙂