Listservs
E-mail listservs are central to the cataloging community. You can subscribe to the "digest" version (messages are grouped together rather than received individually) to minimize the number of e-mail messages you receive, or even subscribe but set a list to "nomail" and read messages on the online archives. You must be a subscriber to post messages or to access the online archives.
AUTOCAT -- An international list focused on cataloging and related issues. You can subscribe here: https://listserv.syr.edu/scripts/wa.exe?SUBED1=AUTOCAT&A=1
OCLC-CAT -- Hosted by OCLC, with a focus on using Connexion and other OCLC tools. You can subscribe here: https://www.oclc.org/forms/internet-subscription.en.html?urlm=168713
RadCat--"Radical Cataloging" listserv, named after the book. Smaller audience, focused more on social and ethical responsibility in cataloging as well as innovative practices. You can subscribe here: https://listserv.uga.edu/scripts/wa-UGA.exe?SUBED1=RADCAT&A=1
BIBFRAME list (see the BIBFRAME FAQ's for information)
PCC lists -- primarily focused on aspect's of the Program for Cooperative Cataloging. More information, including how to subscribe: https://www.loc.gov/aba/pcc/discussion.html
Online Tools
RDA Toolkit (requires login--see shared drive for information)
Classification Web (authenticates automatically on campus)
Best Practices
Best Practices for Cataloging Comics and Graphic Novels Using RDA and MARC21 (pdf) (can also be accessed here)
Best Practices for Cataloging DVD-Video and Blu-ray Discs Using RDA and MARC21 (pdf) (can also be accessed here)
Local Documents
856 indicator 2 decision tree (based on Adam Schiff's documentation)
Cataloging-related training
Library of Congress Subject Headings
LC created this extensive subject heading training for their overseas offices and continues to update them regularly
Library of Congress Classification
OCLC "AskQC" Office Hours recorded sessions from OCLC's Quality Control – learn more about cataloging in OCLC and using Connexion
Each session has a featured topic (such as "when to input a new record," and "small errors with big consequences").