The librarians at the University of Pennsylvania maintain a Library RSS Feed Generator. The main page of this site lists subject areas for which there are research guides (with the most recently updated on top). Each entry on the home page provides links to specific resources, a link to the RSS feed for that list, and a link to all the guides within a broader subject area.

For example, the History category has both an overall RSS feed for guides in history as well as individual feeds for guides to articles, historical image collections, and databases of print advertisements.

Even better, the librarian who curates each guide is listed by name, with an email address and last-updated date displayed on the web page.