The currency in Swaziland is lilangeli, it is there the same time as in Netherlands.
Swaziland has a tropical climate, the temperatures are around 15 to 25 throughout the year.
You must have a passport that is still valid at least 3 months upon arrival in Swaziand.
You should not drink water from the tap in the big city, so buy large bottles of water.
You have all sorts of different inoculations for Swaziland as hepatisis A, DTP, MMR, yellow fever, tuberculosis, rabies, hepatisis 

The country with the highest rate of hiv infection and aids in the world

http://www.opreisnaarzuidafrika.nl/Zuid-Afrika/Swaziland/