For details of the process, read here: http://www.cic.gc.ca/english/immigrate/sponsor/spouse.asp
You'll have more questions after you've read it, feel free to ask more specific ones
For an outland application (processed abroad) it costs a total of $1040 for a sponsorship application with no dependants. That are the fees CIC requires, it doesn't include any fees you'll come accross when preparing the application, including the cost of the medical exam.
Processing times are different around the world, check here for the current processing times:
http://www.cic.gc.ca/english/information/times/international/05-fc-spouses.asp
If your wife is already in Canada on a valid visa (either a work permit, study permit, temp. resident visa,...) then she can stay there until it expires.
If you do an inland application, then you have the option to file for an open work permit along with the application and if granted (usually some 6 months AFTER you file), then she can work in Canada while waiting for the application to finish processing.