I think a beginner can definitely learn and benefit from the book,
but I would warn that it’s not a step-by-step guide like AWDWR or
Rails Recipes. You would probably want to be familiar with the
concepts in AWDWR or have spent at least a few days on a project
using Rails before jumping in to The Money Train.
I may not be the best person to answer this question though, since
I’m rather familiar with the subject matter. 
–
Benjamin C.
http://www.bencurtis.com/
http://www.tesly.com/ – Collaborative test case management
http://www.agilewebdevelopment.com/ – Resources for the Rails community