Henry Ward Beecher, American social reformer (1813-1887) said, "A library is not a luxury but one of the necessities of life." 

Here's a quote about librarians from the famous children's and young adult author, Neil Gaiman: "Google can bring you back 100,000 answers; a librarian can bring you back the right one."

A few more:

• Ray Bradbury, science fiction author: "Without libraries, what have we? We have no past and no future."
• Paula Poundstone, American comedienne: "The truth is libraries are raucous clubhouses for free speech, controversy, and community."
• Laura Bush, former First Lady: "Libraries allow [people] to ask questions about the world and find the answers. And the wonderful thing is that once a [person] learns to use a library, the doors to learning are always open."
• John F. Kennedy, 35th President of the U.S.: "...libraries should be open to all—except the censor. We must know all the facts and hear all the alternatives and listen to all the criticisms. Let us welcome controversial books and controversial authors. For the Bill of Rights is the guardian of our security as well as our liberty."