The Library of Congress (LOC) keeps an Authority Record. By the way, this record is HUGE! It's basically the way the LOC keeps everything level for everyone. They have Authority records for Authors, Series, and Subjects. The have recently stopped making records for Series, but they continue to add subject headings all the time, to the tune of 2,000 to 4,000 entries a year. These headings are as simple as "Automobiles" to something as huge as "Mytocardial infartion" (heart attack). These headings keep everything together. If you are searching for a book in the catalog, the best thing you can do is look for the subject. If you want information on a topic, don't look for keywords because you won't get nearly as many results. Use the subject search and use controlled vocabulary. That means, think about what you want and then you type it in. This shit ain't no Google.
The best thing about using the subject heading search is that even if you aren't looking for the correct heading, the subject records regulary have similar entries. This means that if you look for heart attack in the subject field you'll be told to "see Mytocardial infartion." (Yes I know I've misspelled it twice. I don't want to take the time to look it up. DEAL!)
I learned this in the first two hours of class. The last four hours of class were not even close to interesting. I took the time to look for yarn on the internet, rebid on a phone I'm trying for on Ebay and chatted on gmail. It was a productive online day. I did not get on EW.com, which is a big step for me.Usually I waste whole hours on EW. It's just that amazing.