LTR101 is a very good introduction for a beginner and for an intermediate too. Very clear concepts, good synthesis. In my case, I have found chapters 7 about Web Application Testing and 11 about Resources very useful. I think most people that are learning Hacking (and Web Hacking) regardless the area of interest, learning on their own, searching resources, books, blogs, websites, courses, tutorials, etc. Then, the most needed is a guide, a map for organizing the study. Here is the book for you.