Here are some relevant links and the useful information you can find at these sites.
NUS Global - Student Exchange Programme
Introduction to SEP
Partner universities
SEP application process
List of application periods for each faculty
Financial aid
Preparing for SEP
FAQs
NUS Faculty of Arts and Social Sciences - Student Exchange Programme
FASS SEP application process
SEP application materials
Unit ratios for PUs
SEP admin matters
Financial aid
FAQs
NUS Economics Department - Student Exchange Programme
Course mapping tips
Student experiences