She can try to apply for a visitor visa, but unless she's able to prove she has stronger times with home than with Canada, she will not get one - they will not give a visa if they suspect that the person intends to stay in Canada. And with a husband in Canada, that will be hard to prove. But it doesn't hurt if you try :)
There are two types of applications, inland and outland. Inland is processed in Canada, outland is processed in the visa office responsible for the country your wife is from. For an inland application, your wife has to be in Canada - if she leaves Canada and is unable to return (if for example she doesn't get another visa) to attend the landing interview, then you lose the application and you have to apply again.
You can file an outland application no matter where your wife is, in Canada or not.
An open work permit is available with an inland application - you apply for it at the same time you apply for your wife's PR. If you get approval in principle, then she'll likely get the work permit as well. It takes 5-6 months for Vegreville to get to this point. After that, it can take a month or a year to finish processing, depending on if and where your file is transfered - they transfer it to the local CIC office and some are busier than others. While waiting for this, she would have to keep getting her visitor's status extended.
Personally, I would recommend you start looking into an outland application, so
this one.