The book is just great and I have in total 6 of them.
As said by others before, alone the food procurement chapter and the survival kit chapter is worth to buy it.
Having said this, have a look at the USRSOG web side, there is a lot of information and the USRSOG forum is also very informative. A few fellows of the W&SS forum are also there (including me once in a while)
Beside this, very good books are the survival manuals of the Unites States Marines Corps which are available as PDF in the internet for free of charge.