Craig,
I would also recommend the PPL confuser, but as a back up to the Thoms etc.
As for the maths involved with the navigation, it will really only make sense when you start planning trips for real. Perhaps another PPL at the same school as you will help you plan a navex with them? Until you start actually flying cross country trips it is all a bit of a blur of numbers. Same applies to the Met, to some extent. See if you can get a bit of practical experience of checking the weather for trips under your belt (I'd recommend Avbrief on the 'Net) and it should all become clearer.
Best of luck (and remember, most of us licensed pilots may have passed our exams but we can't build to save our lives
)
DBChopper
