Studying for Exam 70-461?

If you are studying for the 70-461 exam like myself, then purchase Training Kit (Exam 70-461): Querying Microsoft SQL Server 2012 from Amazon.  So far I have waddled through the first 150 pages, some parts requiring more time to absorb than others.  I’ve been stuck on chapter 4 for quite some time as the concepts start to build on each other slightly, but nevertheless moving forward.