Cat. & Reference: Pagination
In the library world, "pagination" is the fancy-shmancy word for "the number of pages in a book" and it goes in the catalog record under the "physical description" section.
Who cares about pagination? Well, readers and researchers care because it helps them decide if a book is right for their needs. (E.g., an 8 page, 80 page, and 800 page biography are all intended for different audiences.)
Book collectors also care, because pagination is an important way of distinguishing between different editions of the same book, and some editions may be more valuable than others.
Librarians also care about pagination because it's an important "match point." ("Match points" are pieces of information that librarians use to determine if the book they have is the same edition as the book another library has.)
When it comes to recording pagination, there is one basic rule: Flip to the back of the book, find the last printed page number, and write that down as the total number of pages, like this:
134 p. ("Pages" gets abbreviated "p.")
Don't count blank pages at the end, don't count unnumbered publisher pages, and don't count the last page if the page number happens to be suppressed.
What about books without page numbers? You have a few options. One is to count the number of pages by hand, and put the total in brackets:
 p. (Brackets mean that you didn't get the information from the "official" source, in this case, from printed page numbers.)
Another option is to estimate the total number of pages:
[ca. 150] p.
Or you can give up and describe it this way:
1 v. (unpaged) ("V." stands for "volume.")
If you have more than one numbering system in the book, give the highest page number of each numbering system (this is really common with books that have prefaces or introductions):
xiii, 264 p.
Or if there are too many numbering systems for this to be practical (say, more than three), do this:
1 v. (var. pag.) ("Var. pag." stands for "various pagings.")
So, with that toe dip into the exciting, fast-paced world of counting book pages in a library setting, how would you deal with the following situations:
1. Alan Fletcher, writer and book designer of The Art of Looking Sideways includes page numbers in this book, but with a catch. Instead of numbering every page, he numbers every spread (group of two pages). So the book says it has 533 pages, but in a normal book it would actually be numbered 1066. How you you describe this so that patrons know the book is much larger than the page number would lead them to believe, while still being true to the page numbers printed in the book?
2. You're cataloging an article on salmon net-pens (lucky you!) and the last printed page number is 157. However, this article was reprinted from the scholarly journal it was originally published in and it's not actually 157 pages long, it just spanned pages 147-157 in the original volume. How do you describe this?
3. Michael O'Brien's biography of John F. Kennedy is 971 pages long. However, it also includes an extra 16 pages of photographs printed on special paper in the middle of the book which don't have page numbers. How do you include this information? (Bonus points if you can explain why it's exactly 16 extra pages, not 15 or 17.)