about the tax (tax rate etc), you can get the information in IRAS website

http://www.iras.gov.sg

税单寄到家里－－一般是IC上的地址

How do I update my personal particulars?

You may call our Individual Income Tax Helpline at 1800-3568300 during our office hours from 8am to 5pm from Monday to Friday; and from 8am to 1pm on Saturdays or email us. If the update is a change in name, please send or attach a copy of your NRIC, Deed Poll or Passport. You can also write to us at:
Inland Revenue Authority of Singapore
55 Newton Road
Revenue House
Singapore 307987

如果我的理解没有错的话，报税和缴税是两个不同的概念，报税是呈报你的收入之类，算出应该交多少税之后在一定时间内得去缴税。没有或者推迟报税/缴税的话，都会有麻烦

http://www.iras.gov.sg/ESVPortal/iit/iit-se-a1.1.20+penalties+for+late+or+non-filing+of+it+forms.asp
↑What are the penalties for late or non-filing of income tax form

http://www.iras.gov.sg/ESVPortal/iit/iit-enf-v.a.1+penalities+for+late+or+non+payment.asp
↑What are the penalties for late or non-payment?