Keep on hand the following documents:
* Your Passport
* Your CoPR
* Your proof of funds
* Your medical certificates
* Form B4 (Two copies each)
* Four passport sized photographs (make sure these meet CIC's specifications)
* Your customs card (you get this on the plane)
In addition, having the following on hand means you will be prepared for just about anything:
* Copies of correspondence with CIC
* Copies of all degrees, ECA assessments, PCCs, etc.
* Receipts for the Canadian currency you are carrying on you, if any
* Prescriptions for any medicine that you may be bringing into the country, if any
* Receipt or confirmation of the address where you will be staying (which is presumably also where you are getting your PR card delivered)