There is a publication from Ministry of Foreign Affairs of Singapore (MFA) that you can refer to here. Here are some points to take note of, which apply regardless of whether you are a Singaporean or another national living in Singapore:
- Your passport validity/expiry;
- Visa requirements;
- Vaccination requirements/recommendations;
- Bring-out/Bring-in cash/currency limit;
- Customs duty;
- Quarantine requirements;
- Proof of return ticket;
- Local weather;
- eRegistration with MFA (for Singapore citizens, here); and
- Registration with ESTA, Electronic System for Travel Authorization (for those travelling to USA, here).