Just from my experience as a beginner ( kind of but not ) I would check out chris' lessons on scales here at GT.....I didnt notice if you were a full member...you could pay for a month of lessons here for less than the price of one scale book!
start with one and learn how it is applied to the fretboard and how you can move the scales around.
I have had several books and approached scales from different places...and they just get messy and overwhelming.I mean they really are important and there are soooo many and if you get certain concepts down its easier to apply them....take it in small bites as chris presents it here it is easily understood and well paced.