Here are some preservation methods for material in general collections:

Library Binding - Think of bound periodicals. Check out all the different colors of buckram available at the Library Binding Company.

Microfilming - Everyone at some point has used one of those clunky machines to look at some old newspaper. Let's hope that LOC's US Newspapers Preservation Microfilming Guidelines were followed.

Photocopying - This preservation option is relatively inexpensive and not too exciting. Of course, guidelines, provided by ALA, apply here also.

Finally, some libraries can do in-house repairs if there are minor problems like loose pages, tears, or broken hinges. But, you have to be familiar with the parts of a book.