Enabling RSS feeds
Make sure Site Wide syndication is turned on using portal_syndication tool Properties tab. It should already be, as it appears to be the default (contrary to scanty documentation). Once this is done. then all plone folders should have an RSS enabling action...
If they don't then use the cludge
to enable it.
The feed is then available at foldername/RSS.
If you want something more complicated than the contents of a folder to be syndicated (and there's no way of filtering our images, boxes etc at the moment), then the best way is to create a coillection/topic which displays the stuff you want to syndicate, and put enable syndication for that.