I study the book rather than the questions to be honest. I read the book once, do the exercises, then go back to the bits I'm still not sure about, then read the book again, maybe go through the questions in confuser twice and then write the exam. This way, the knowledge will actually stay in my head!
I'm definately thinking of doing Nav and Met whilst I will be doing that bit in my training.
About the timing, I'm hoping to get my license by the end of maybe.. october? so even if I'll write an exam per month, I'll get them all passed before my skills test.
Vems