The Buses from David to Boquete are of the "Diablo Rojo" type, in other words, recycled US school buses. Not comfortable as the seating is spaced for grade school-sized children, not adults. If you are over 5 ft tall (1.6 meters) your knees will hit the seat in front of you. Not very comfortable, but it is cheap ($1.45 USD per person - one way) and not that long of a ride, about a half hour to an hour depending on how many stops the bus makes along the way, it is not an express route. They run about every half hour on the hour and 30 minute mark fm the main bus terminal in David. Gate 15. It's almost dead center in the long row of buildings which is the terminal. The road fm David to Boquete is in very good condition most of the way so it is not a bone-jarring ride. The bus terninal in Boquete is in the middle of town, and an easy walk for anyone in reasonalby good condition to nearly all the hostels, hotels and pensions in Boquete. This is a reasonable alternative to taxis. If you have a lot of luggage, you may want to use a taxi, however, as the buses have little storage will just take your bag to the back and leave it in the aisle. If you don't want your stuff stomped on, then maybe you should consider the expense of a taxi.
Buses from David to Boquete take 1 hour and the fare is 1.4$ From Boquete to David buses start from the northern side of Boquete central square, and run every half an hour from 5:00am until 6:30pm. You can also catch it on the main road. Just wave to it and it will stop.
There is a local bus that goes up the regional hills for 0.50-1$.
If you want to visit Cerro Punta or Guadelupe you should have to move through David because there is no direct bus from Boquete to Cerro Punta. David to Cerro Punta takes about 2.5 hours.
Access to Costa Rica is possible through David. Direct buses to San Jose depart every morning at 8:00 and take 8 hours for 12.5$. There is also a picturesque but adventurous passing through river Sereno on Volcan Baru but you have to ask the locals at Cerro Punta for more info.
For Almirante (and Bocas de Torro) there are hourly buses from David and take you there in 4 hours.
I traveled from Bocas Del Toro to Boquete by taking a water taxi to Almirante (easily scheduled in Bocas) and from there catching a bus to David (simply ask a taxi driver in Almirante to take you to the buses). In David there is a fairly large bus terminal where you can find buses going most anywhere, including Boquete. The water taxi ride is about 20-30 minutes. The bus from Almirante to David is about 4- 4 1/2 hours, depending on weather, with a break halfway through. The bus begins air conditioned bus as you get into the higher altitude the windows are opened. The buses are fairly comfortable, though the hour bus ride from David to Boquete is on an old school bus, which is not air conditioned, but even if you flew to David (closest airport to Boquete) you still must take this bus to Boquete. With all the scenery along the way, the bus ride is enjoyable.
Getting around Boquete, once there, couldn't be more simple. The town is quite small, and you can easily walk to any in-town destination quickly. You can take a taxi to the Park, or you can hitchhike. Hitchhiking in this area is very safe. Everyone I encountered was more than happy to have me ride in the back of their truck. Nearly everyone in this town will be more than willing to give you directions, and possibly walk, or drive you there.
We leased a car at the David airport and drove over to Boquete.
It was dark when we arrived so we had some problems finding street signs but other than that no problems at all.