The Official Guide was published a few days ago and joins publications such as Expert Golf’s quick reference guides www.expertgolf.com and video
https://youtu.be/chPOtfLUHC0 which summarises 20 of the most important changes. The Video is really worth a watch .
And then. of course, you have the official websites from The R&A and USGA and the publications available in more than 30 different languages !
Ignorance will be no excuse!