I was in Palawan for a week earlier in May this year - loved my time there!
I flew into Busuanga on Coron from Manila, spent 3 nights there, then took the ferry down to El Nido and spent another 3 nights there before taking the early bus down to Puerto Princessa, did the Underground River tour, spent a night in PP and flew back to Manila the next day.
Here are some photos of Palawan :-
Lake Kayangan in Coron (Tour C)
Getting around on the Filipino traditional 'bangkas'
The crystal clear waters of El Nido