Get a technical overview of the popular Atom Syndication Format. This article discusses Atom's technical strengths relative to other syndication formats, and offers several compelling use case examples that illustrate those strengths.
This rxml template (modified from the one in blinksale.com) generates valid Atom 1.0 feeds. If you have a partial to create HTML for each item, they can be included in the feed's "content" elements.
This is the W3C Feed Validation Service, a free service that checks the syntax of Atom or RSS feeds. The Markup Validation Service is also available if you wish to validate regular Web pages.