Forum Moderators: open
1) In your robots.txt make a reference to your sitemap by adding the line "Sitemap: [domain-name.com...] (without quotes)
2) When you change the sitemap name, remember to update it in Google Webmaster Tools, Yahoo and MSN Live webmaster accounts.
The only reason I'd recommend a sitemap name different from the default is if you have more than one XML sitemap for your site. Otherwise, no real point in doing so.