FOR BUS SCHEDULES BEYOND ATENAS you English speakers are lucky that there is one in English available at http://thebusschedule.com/EN/cr/index.php  in which you fill in the form for where you want to travel, the date and time of day and they will give you a bus itinerary for your trip and often several options. It is what I use to plan my trips. It couldn’t be easier, but some Americans are still afraid to try the buses which go to almost every town in the country. This is the way local people travel! And yes, it is slower than going in your car but at an enormous savings and I would say generally safer plus more social with more cultural experiences and certainly more relaxing than driving. Where I do spend the money (still cheaper than a car) is to avoid some long bus rides I will take one of the local airlines to more distant places. Lazy old man! 

One of the Coopetransatenas Buses leaving the Alajuela Station In San Jose there are lots of other bus companies to other towns and most have similar equipment, from Germany, China or Korea usually