Anything by Phil Rozek is gold. I would spend a lot of time on his blog (he has some downloads too), I would read Linda Buquet's forum/blog, Mike Blumenthal, Andrew Shotland...the list goes on. Even Darren Shaw has a few good posts. Nyagoslav Zhekov kills it, though now he blogs for Darren/Whitespark...his old blog is still around I am sure (NGS Marketing or Optilocal). There are some good guides, though I have read very few. Even when there is a lot of substance, it is mostly regurgitated, repackaged crap. Max Minzer has a great Google+ group which discusses all things Google Local. Tons of smart people there. The resources are endless.
Happy reading : )
-Adam