I'm working on a free, short guidebook called "Grokking OS X." It deals primarily with tweaking your OS X install to the way you want it, and covers topics such as the Finder, Spaces management, Exposé, Mission Control, Autosave, Mail, and Preferences. In addition, it also shows system-wide OS X defaults like customizing toolbars. Essentially, it's a guidebook to make newer versions of OS X feel like 10.5 and 10.6 again. It's a PDF and licensed (c) 2013 Kunai from MacRumors, all rights reserved currently, but I will change the licensing to CC Attribution once I'm finished with the first edition. I've attached a beta copy that deals mainly with the Finder sidebar. It's still at a very early stage, so don't hesitate to tell me if something is wrong. If you found it useful, please leave a comment and tell me that you liked it. Thanks for the feedback.