Come into SG, start work, get your employer to sign your IPA, while working do your medical checkup, once confirmed no HIV or TB, make appointment with EPSC, turn up to EPSC at Riverwalk, give photo and all documents, done!
This is simply your immigration white card (30 day validity) that any visitor gets when entering SG.

Do you have the in-principle letter with you ? you can show that to the immigration officer (SG side) and they sometimes don't even bother processing the white card (happen to a friend of mine). Just fill in everything and leave it to the officer on what he want to do

FYI, the white card will be taken away when your documents are processed in EPSC, so when you exit Singapore after getting your employment card, they no longer need to stamp your passport (so you have entry to SG stamp but not out )

Good luck in on your adventures in SG