All visitors to Singapore should hold a passport that is valid for at least six months after their planned departure date from Singapore.
Nationals of EU countries, USA, Canada, most Latin America countries, Australia, New Zealand, South Africa, Israel and Japan are not required to obtain visas in advance and will be given a social visit pass upon arrival, that allows them to stay in Singapore for a period of up to thirty days (extendable).
Customs in Singapore is quite simple and hassle-free. If you have nothing special to declare you may just proceed.
For more information, please refer to the Singapore Customs website.