Missy27 - If you are a Singaporean citizen, then you will not need a visa, since Singapore is a visa-exempt country.
However, you will still have to meet admissability requirements (the link Johnny31 has below should show you to them)
If you are NOT a Singaporean, and not from an exempt country, then you will have to apply for a TR Visa to visit.
Good luck, and I hope this helps!