start here:
http://www.cic.gc.ca/english/immigrate/sponsor/spouse-apply-how.asp
click on "get the application package" and choose the package for OUTSIDE of canada. you do NOT want the INSIDE canada package. There is absoultey NO reason for a us citizen to apply INSIDE canada right now, so you want to apply OUTLAND.
You will want to read the "guide to sponsorship" first. there is A LOT of information needed, and until you read the guide and application forms, we will not be able to help you specifically. it is better to ask specific questions once you get a general idea of what is required. The application forms can be filled in by hand or on the computer.
The applicant will need to get an fbi record done and a medical exam by an approved panel doctor (list is provided in the guide). The fbi record is only valid for 3 months, so you need to coordinate when you receive it with sending in your package. currently, fbi records are being completed in 30 days, not including mail time. They must be requested directly through the fbi.
go here for how to get one:
http://www.fbi.gov/about-us/cjis/identity-history-summary-checks
What i can tell you right now is that us applicants are processed through the OTTAWA visa office. They are NOT sent to LA unless there is a concern with the application and an interview is required. NY does not process family class apps anymore, so if there IS an interview, it WILL be in LA. Generally, us applicants are waived the interview. the most common reasons for interviews for a us citizen is related to non-accompanying minors, criminality issues, or if the applicant is not a us citizen (the APPLICANT is a green card holder or in the us on a work visa).
Right now US applications are being processed quickly. Currently the trend is 3-6 months for approval. The processing time does go up and down based on the number of applications received. the application processing times on the CIC website are highly inaccurate and do not reflect TODAY'S PROCESSING.
Again, read the guide, get familiar with the forms, and come back with specific questions if you have any.