Here is an interesting article, Search-engine savvy librarian shares some of her expertise by By Pam Mellskog, The Daily Times-Call.

Ellen Bates, the librarian, is hired by companies to find information. She has long since abandoned using Google, saying “The secret is, you don’t do a Google search. You go to where the information is. There’s the invisible web, and Google doesn’t have a library card.”

She prefers directories over search engines, “A search engine spider is not creative,” she explained. “It doesn’t initiate or interact. They don’t type. So, anything that requires an ID or password, it will never show up. All a search engine spider knows how to do is to go to a page and search all its words.”

The article lists some internet directory sites as well as some invisible web sites. It is a neat little article in that it is just another hard example to show your administrators, powers that be, or your patrons that Google doesn't have everything.