For what it's worth
My own personal journey through the Pratt books:
1. Air Law - You need it for Solo. It's also quite interesting
2. Radio Telephony - Should've left this to later, it's pretty hardcore, but easy when you get into the swing of things
3. Navigation. Makes sense of a lot of things
4. Radio Telephony - CAP416? - Getting to grips with it now
5. Metereology
All of the while I've been reading PPL1 back and forth throughout.
My first FI told me to read chapters 1,2,3,4,5 the first week (a chapter a night) and then 2,3,4,5,6 the following week etc etc.
Fair play to anybody who is going to do the exams with zero flight time, I've now idea how you guys do it. It's impossible to make sense of all of the theory if you never see it exercised....