If you mean the Pilot' Guide books, I have the C152 one and I find it a good resource to all you need to know about the aircraft, kinda like a mini POH, I would say for 8 quid its worth every penny.
However there is a danger that people will use them instead of the POH/FM, so use it as a reference and go on what the POH/FM says. There is a lot of handy information in it and it makes interesting reading.
Hope it helps,
Rusty
P.S, spooling is probably awfull in this.