Since many of you are wondering what you can do to prepare for Google Summer of Code (GSoC), I thought I would send out some recommended reading for both would-be mentors and would-be students. Hope it is useful to you. If anyone else has suggested resources, please suggest them in this thread.
Reading for Mentors:
In addition to the program wiki , you may find the Mentoring Guide for GSoC  very useful. The guide is especially helpful for new mentors, though it has been written to be helpful even to those experienced with GSoC. For brand new mentoring organizations, please do peruse our notes on organization selection criteria document. 
Reading for Students:
There are many great resources for students, including the program wiki.  If you are brand new to the Open Source world, you may find the book Producing Open Source Software  very useful. I have also found the talk Poisonous People  to be a great resource for learning about ways that you can do things well to make a good impression in a brand new community.
There are also various guides on Netiquette  out there, and well known documents like How to Ask Questions the Smart Way.  Other folks might recommend reading the Free Software Definition , the Open Source Definition  and the Cathedral and the Bazaar  for more background on Free and Open Source Software (FOSS) from a historical and legal perspective.
And for those folks who are more visually oriented, there are many useful videos about GSoC and the various projects that have participated in the past as mentoring organizations available in our Open Source Programs Office Student Programs YouTube Channel. 
Hope some of these resources are helpful to all of you!