TeamMattronica

Fibelbs: Yes they did! Everything was accepted and is processing as far as my case number tells me :-) GOOD LUCK!

The government will know where to find you as you file your last tax report, put your new adress in the US on it. For all the administrative services (healthcare, income tax) in Quebec we can do it online once and it will give your new address to all administration services. It probably exists in all regions
 
 
 

~~Moved to the Canada forum from Off Topics~~ 
 
mod hat off
 
There is nothing you need to do before you move, other then make sure you stop the GST (what ever it's called now) and the child tax credit before you move. They are not something you get to keep when you move and they will want the money back if they keep sending it. Plus sometimes it takes calling them more then once to cancel. 
Once you file your last  Canadian taxes you will mark your exit date.

As someone has said, the police certificate will likely have expired by the time it is needed. Your I-130 is going to take around 6 months to be adjudicated, your case will then be sent to the NVC and it will be needed there but that's about 7 months away. 
 
Likewise the I-864 will need to be redone because by then it will be after April 18 so it will need 2016 tax return information. 
 
At this stage you are focusing on the petition - in other words your eligibility to sponsor an immigrant. You must satisfy USCIS that you are:
a) either a USC or an LPR
b) legally married to the person you are hoping to sponsor 
c) married to that person for love and not to help them get into the country 

About Police clearance certificate; it generally is only valid from six months to a year. You might need to make one again at a later stage. So, before you send PCC at NVC stage, remember to check the validity.

I would include W-2's also. 
 
Have any of you been married before?