Before engulfing yourself in pages and pages of threads & info, bickering and outdated information, I recommend creating a My Disney Experience Account and familiarize yourself with it. Get a basic understanding of what it is and what the changes are, the use the boards for research on more specific topics.
What is important to remember is things are constantly changing, so don't worry about the specifics yet, because by the time you understand the new system as a whole, it is likely the specifics will be different.