Kev, sorry to take it a bit off thread!! As you'll be at a civilian airfield we're probably totally confusing you with talk of oval circuits........
Thats a bit condescending; although clearly no offence intended.
I prefer oval circuits as the norm: quicker so can fit more into the measley hour or so. That said many (most?) civil flying schools will teach glides from an oval circuit but from normal circuit height. The military types tend to take an extra 500' for a glide practice.
As for exam prep and study, read the books (Trevor Thom) and do the practice questions in the back pages. A lot can be gleaned from these forums but see what agrees with the books and what makes sense to you. Sometimes the wealth of experience from some here is staggering, and advice will more than likely be a little more complicated and indepth than what the PPL exams require. If you are left in doubt ask your instructor.