So it means no form is needed for my 4 year old son?
Yes. As stated in the form.
And which form did you filled up for your 4 year old? is that Application for a Temporary Resident Visa-Schedule 1?
I have included this forms in the package:
Document Checklist [IMM 5484]
Document Checklist – Applicants in Canada [IMM 5721]
Application for Temporary Resident Visa [IMM 5257]
Family Information [IMM 5645]
Schedule 1 - Application for Temporary Resident Visa [IMM 5257 - Schedule 1]
Also, include Birth Certificate, Passport, Passport size pictures
Read this site. This is very informative: http://www.cic.gc.ca/english/information/applications/visa.asp
and the guide http://www.cic.gc.ca/english/information/applications/guides/5256ETOC.asp
and lastly, how much did you pay for the visa for your 4 year old? (I've heard they have separate envelope and manager's check both for my wife and son)
First, don't just eavesdrop. But the information is correct. When you call PIASI they will inform what to do with your wife's and son's envelopes (check this site for the numbers: http://www.canadainternational.gc.ca/philippines/visas/apply-how_demande-comment.aspx?view=d. Like what to write, what to include, it is ok to have more information or more documents for proof. I paid 6,100 Php for multiple entrieshttp://www.canadainternational.gc.ca/philippines/visas/fees-frais.aspx?view=d
More information here: http://www.canadainternational.gc.ca/philippines/visas/index.aspx?lang=eng&menu_id=3&view=d