Exactly.
I used the Lonely Planet Guide as my bible during my early visits to the Phils, and also bought the other Asian LP guides when wandering further afield.
Excellent books, if a little heavy. No internet then of course.
The other well known series is the 'Rough Guide' books, not as detailed as the LP ones though IMO.
As I've mentioned before, 'Imelda' (Biography) is a really good read for those interested in the Marcos era and the excesses of that family.