A rich lowland savannah patched by deciduous forests stretches along the Pacific coast between the two peninsulas. Costa Rica's weather is influenced by altitude. The Pacific coast is drier while the Atlantic coast has the most rainfall - about 300 days a year. The wet season is from May to October. The hottest months are March and April.
Earthquakes usually occur during periods of seasonal change.
I always use Travelocity. Check their site, it has a lot of valuable information. Both car and eight person mini-buses are available for hire at the airport for transport to hotels. In addition, most big hotels have a mini-bus service to and from the airport. In San Jose and other provinces, you can travel by taxi.