Ouch!! I had a bunch of stuff jotted down and then my browser closed!!! First of all, here is my advice on visiting the USA
Canadians Visiting the USA while undergoing the visa process, my free advice:
1) Always tell the TRUTH. never lie to the POE officer
2) Be confident in ur replies
3) keep ur response short and to the point, don't tell ur life story!!
4) look the POE officer in the eye when speaking to them. They are looking for people lieing and have been trained to find them!
5) Pack light! No job resumes with you
6) Bring ties to Canada (letter from employer when ur expected back at work, lease, etc etc)
7) Always be polite, being rude isn't going to get ya anywhere, and could make things worse!!

Have a plan in case u do get denied (be polite) It wont harm ur visa application if ur denied,that is if ur polite and didn't lie! Refer to #1
Be prepared to answer questions on how you are going to support yourself, and whom your seeing. If he isn't your fiance, I would not expect to see a ring on that finger,lol But NEVER LIE!!!!!!
Visajourney is a great FREE forum for relationship visas! Many think these visas are fast, but they are not!
K1 takes anywhwere from 6-8 months on Avg and a CR-1 is 7-12 months!! The paperwork is fairly easy, its the waiting thats a pain!! And yes you can file while your in the USA!! We had a courthouse wedding while I was in the USA and went the CR-1 route. Then later on, had a big family wedding. k1 route is faster, but has its drawbacks. I will post a comparison link!
http://www.visajourney.com/forums/forum ... rocedures/http://www.visajourney.com/forums/topic ... -and-info/http://www.visajourney.com/content/comparehttp://www.visajourney.com/forums/forum ... rocedures/You will see a K3 forum, but disregard, its gone the way of the dodo bird!! Why? process takes the same length as the CR-1(ir-1) BUT it costs more and more paperwork involved!!
You will read about how some entered the USA as a tourist and then stayed and then simply Adjusted of Status (AOS) Is it Legal?? Yes and No! It all depends what your INTENTION was when you enetered the USA. If you had NO intention of staying, then out of the blue u got married, one could AOS. BUT if you had the intention all along of staying, then its not legal! How they truly figure that out, do not know! I never preach lieing!! If one goes that route yest it is faster, I heard like 3 months till u get ur greencard, but keep in mind you can't leave the USA until u get the greencard. Well u can leave, you just may not get back in!
You will find that most of us Canucks visited our spouse a fair bit during the process, and everyone will say yes it sucks not being together all the time! Just part of the process! If you went the k1 route, you could stay together for most of it (if they allowed u in for the whole 6 months)
For the K1, the interview takes place in either Vancouver or Montreal! Manitoba and west goto Vancouver, which is a LOT faster than Mtl!! If u go the CR-1 route, ONLY montreal does the interviews. USA person does NOT have to be at the interview!
All the info for K1, CR-1, AOS can be found on VJ. At the top, there is even an EXAMPLE FORMS link!
Best of luck