A comprehensive database of library collections. 15,637 libraries and 512 million bibliographic records. Over 3 billion library assets. The video below notes that over 100 million people utilize this research resource. You can set a profile and categorize your materials as well. It's also a citation engine. The video below also provides information for Indie Authors to know and a topic discussion on getting self published books into the local library system.
I first heard about WorldCat when I was enrolled in my graduate program at NMSU. A friend of mine was using it to search for books and it was something that I too began using to locate certain books. Now that I spend more times day to day with audio books then I do physical ones, I still like to reference physical texts by searching for them locally or regionally through WorldCat. My next step is to set up a profile and to take advantage of this space and time to organize my own personal, academic and professional literary interests.
A link to WorldCat is now visible in the side bar. worldcat.org