yes, only buy the offical second edition of the book, you can buy a pdf version of the book with just the chapters you need, as you don't need to read the whole book (off ebay - many on here, my wife used the first ed off these people http://cgi.ebay.co.uk/LIFE-IN-THE-UK...QQcmdZViewItem )

since may/june of this year you couldn't use the first edition of the book, as they expanded the test to cover more chapters that were only in the second edition.

there are many good web sites out there with sample questions and info on
e.g
http://www.lifeintheuk.org/

good luck but do it sooner than later, becuase i'm sure they will push the price up for the test.