By now, we librarians are familiar with the single-line form, the consolidated index, which represents a very large portion of a library’s print and online collection. Our end users certainly are familiar with the idea of a single search across a comprehensive index that produces a large, relevancy-ranked results list. Even though most patrons would not recognize the term web-scale discovery (WSD), it is what they have come to expect. More and more libraries are stepping up to meet their users’ expectations by implementing WSD services. Librarians around the world are trying to learn what these services are and how they work, evaluating the services on the market, selecting and implementing a service, and then teaching colleagues and patrons all about it. This is just what I needed to do in my position as the electronic resources librarian at the University of Central Florida. Based on my investigations, this article explains WSD concepts and terminology, shares findings from my interviews with major WSD vendors, and provides a template checklist, which librarians can use during their own exploration of these systems.