For Day Trips and  vacation packages around Costa Rica the most common way to make reservations is throught the different travel agents aproved by the Costa Rica Tourist board or throught the recepcionists of the different hotels. If you are interested in a Multi day vacation package to Costa Rica the best way is to use a recommended tour operator from Costa Rica. The biggest ground tour consolidator is Expediciones Tropicales wich has been in operation for more than 15 years. Expediciones Tropicales works in cooperation with costaricaguides  phone in the u.s 1-877-281-8515 in Costa Rica 506-2257-4171.