I tend to rely on City Planner Plays, and then Biffa, for hands-on explanations or analysis.
There has to be other sources of solid content - what is your preferred source of information?
I may give the dev diaries a read-through today, but I strongly suspect the content creators have already done a credible job of surfacing the bits that matter.
Overcharged Egg is my favorite content creator. Not only are his cities beautiful to look at, he also manages to express his excitement for every little thing in his city in a believable manner.