How do we catalog books?

You will have to have the item in hand, if available. This time I will discuss monographs.
Title page and the verso are usually the best source of how one goes in gathering information.
Anglo American Rules are the "software" of the intelligent information, MARC is the "hardware", or the container, storage of that information.
Usually the last revision of the AACR rules should be treated as the valid and credible one.
Monographs are build up on several elements. Some of the information taken from the monographs should be considered vital for credible interpretation of the item, and consists of:
Title, Author, Edition, Publication place, Physical description, Subject and International Standard Book Number or ISBN.
MARC tags for these elements are shown in the same order as the text ones above.
245, 100, 250, 260, 300, 650, 020
For more information on these please consult MARC 21 format for Holdings Data http://www.loc.gov/marc/holdings/ and the AACR2.

Anyone is welcome to add and edit this post.