I'm about to get started learning Processing but I'm just a bit confused as to what book I should start with, as well as what version of the program I should begin learning on. 

I know that Processing 2 was recently released, the 2 books I was thinking of getting were "Getting Started with Processing" and "Learning Processing". However these titles were released in 2008 and 2010 respectively. I am wondering has the program changed as to make certain parts of these books obsolete? or do all (or the majority....) of the examples in these books work with Processing version 1.5 (the oldest version which is currently available for download).