Coming from a beginner, I have to say that what I am seeing in some books are a lack of a thorough subroutine chapter. The camel book (3rd ed.) seems to go straight into tricks of the trade without laying out the basics. And I was a bit suprised at that since I found the pattern-matching chapter so well written and informative. So, I checked out the SR chapter in the llama book (3rd ed.) and again I felt as though I didn't get a full understanding. Maybe its just me being a newbie, but the pattern-matching chapter managed 77 pages while the subroutine chapter pulled out a measly 16 (in the camel book). I would like to see a mastering chapter for subroutines, one to put the others to shame.