following are some links to the official Rules of Golf 2019 changes and some web sites and newsletters to keep you updated with the latest changes and rulings
Rules of Golf 2019 (The R&A)
Rules Overview (The R&A)
Rules of Golf 2019 (Golf Australia)
Full Rules and Interpretations (USGA)
Oswald Academy (website and free newsletter)
20 Must Know Rules of Golf changes for 2019 (The R&A)
Ask Linda: Golf Rules You Can Understand (Blog and free newsletter)
Video summary of new rules (2.5min) Golf Australia