job transfer from Canada to US

I live in Canada and am looking to move to the US as a visitor for a year since it looks like I can't easily get a visa to work (correct me if I'm wrong???). I found a company in the province I live in that has a location in the state I want to move to.

How much paperwork is needed to go through this process? Is it difficult, does it take a long time?

I called the company and they told me that when I get to Phoenix, I can apply right away and if I am hired, I will be issued a temporary Green Card that I can renew. I was sort of skeptical of this : o Can anyone provide some insight/links to confirm this? Thank you!