1. Read Thom Books. Do the progress tests at the end of every chapter. If you're not getting them all right, go back and re-read what you need to.
2. If you've completed the above correctly, you won't even NEED the confuser, but...
3. Read the confuser. It's pretty good.
There are other publications available which are essentially the exact exam questions, with detailed answer explanations, but being able to pass the exams is not the same thing as knowing the subject matter. If you're going on to commercial, the base knowledge from the PPL exams will slash your study time by a not inconsiderable margin, so it's best to just get your head down and put the hours in.