From expirience:
I have a few marks on my record and am in process of immigration to Canada.
If the conviction is over ten years old and no other convictions exsist, he can apply for criminal rehabilitation at the border, the same for a temporary resident permit. It will cost $180USD and he must have all information at that time.
DUI is considered serious criminality in Canada, and he may have to apply for rehailitation through a consulate. This is a long process, too.
But, because he is also wanting to wrk in Canada, a work permit will be needed. There are two ways to do this:
First, apply himself. This will cost between $450 and $900 USD. Of course, his legal issues will have to be dealt with first.
Second: If he has a prospective employer willing to hire him, the employer can apply to Service Canada for him. This costs nothing and is much, much quicker, ususally less than 30 days. Service Canada then contacts local employment offices to decide if there is insufficient skilled workers available for that chosen field. If workers are available and there is no shortage of workers for that field, the application is refused.
If it is found that a reasonable search for Canadian workers skilled in that trade proves there is a shortage, and if his DUI issue is overcome, the application is approved and the employer and applicant are notified. The work visa can be picked up at the border, or mailed to the immigrating employee.
The work visa is good for 6-36 months only, and renewable once. It is advised he gain "landed immigrant" status before the first visa expires. By doing so, he is allowed to stay and work in Canada for as long as he choses. He can hold any job, without visa, except Federal jobs and cannot vote. Otherwise, he is baiscally a Canadian citizen.
Of course, if he has $1,000,000 laying around, he will get immediate access on a plan that he is to open a legitimate business there.
More details can be found here:www.cic.gc.ca

