You laptop will work just like at home, in Costa Rica. The electricity is the same, 110 volt with the same outlets.You might find a cybercafe that lets you plug into their network and an occassional hotel or bed and breakfast might have wifi. You might pack a (cheap) wifi router or two and donate them to any bed and breakfasts that you stay at which are in need!
The SJO airport has free wifi though you need to register first and finding a plug might be difficult.
Make sure your insurance covers loss, damage or theft in a foreign country before you leave.