If you are planning to drive to Pagsanjan, make your way to SLEX and take the Calamba exit. Follow the directions in the map. :) You take the highway all the way, and stop at the municipal hall at Pagsanjan. The resorts/accredited providers would be close by. You can stop at the municipal to ask for the accredited ones so you are not overcharged.
There's no other way to go to Pagsanjan falls but to use one of these "bancas". They are navigated upstream by the "bangkeros". I am sure the trip alone will leave you speechless. It costs 500 pesos at that time but considering the skills of the bangkeros, I think its well worth it. I think this same river was used in the war movie Apocalypse Now.
In crossing to the falls, you need to take a bamboo raft. The raft can accommodate as much as 15 persons per trip. This is optional as some opt not to go near the falls and would rather admire from afar.
The falls trip costs an additional P25 per person which is paid along with the boat fee prior to leaving dry land. Thus, if you will go all the way to the falls, total package cost is P750 per person.
Before you can reach the waterfalls, you need to take a 45-minute boat ride down the river. The trip costs P725 per person inclusive of the following: boat rental, seat cushion, life vest, fuel/motor, and supposedly, boatmen's services. A boat can accommodate a maximum of 3 persons. There is no specific schedule. As soon as you are ready, off you go.