Hello, I am just in the middle of preparing for the PPL ground exams myself. I would recommend you do one exam after the other.
I am now preparing for the aviation law exam amd that's how I am doing it: Currently I am working through the chapters in the Trevor Thom book. I read through the whole book in one go and now I am revising chapter by chapter and work through the questions. When I have done this I will do all the questions in the PPL Confuser. Where I can't answer a question I will revise the relevant parts in Trevor Thom again. When I have done this I will do the PPL Confuser again. When I get enough questions right I wil then read through all the questions and answers in the Confuser again before I sit the exam. I did the same for the human performance exam last weekend and it worked fine for me.
Do the human performance exam first. It is fairly easy (provided you have done your studying)and it gives you a boost of confidence when you have passed it. Then do the aviation law exam (At my flying school these are required to be able to fly solo).
Then go for the meteorology exam - not too much to study - before you attempt the navigation exam which is quite a bit to take in. Both of these exams you probably need to have passed to be able to fly solo cross country.
After these I will probably do the flight planning exam before the aircraft general exam which seems to be another big chunk to digest. The order in which you take these two exams is entirely up to you, so do them in whatever order you are most happy with.
When you have mastered all the above exams, don't worry, the fun is not over yet. There are still the written and the oral radio telephony exams to be passed before you can do your PPL skills test.
Have fun, and good luck.
GAF4139