Library of Congress
Resource on understanding MARC principles, as well as reference materials for most used MARC fields.
Authoritative resource on everything MARC, from general information to RDA in MARC.
Explains the process of CIP - informative for how much can be expected for a resource, and what you'll need to add.
Portal site on the LOC website with over 25 links pertaining to cataloguing.
Online Computer Library Center
Portal site with both OCLC and non-OCLC resources on RDA. Includes overview and training resources
Extremely useful reference tool to use while inputting data into MARC fields. Each field and subfield is defined, and examples are provided.
Contains the DDC Introduction, the Summaries, and updates. Also has other resources.
Association for Library Collections & Technical Services
Collection of cataloguing resources from the library community's definitive technical association.
Portal site of cataloguing resources geared specifically to librarians working in school libraries or children's/YA departments.
Explains current and previous updates to the DDC.
Portal site for various trainings on RDA.
Takes you to the search results page of searching the School Library Journal for the word "cataloging".