If your family is Canadian Citizen then they Entitled for Visa on arrival. Initially it is 1 month. You can extend it total 4 month. When your company will Provide your work visa you can take them with as I mentioned above. After coming here try to proceed for their resident permit. You will get all information on below link.
http://dohahamadairport.com/airport-guide/at-the-airport/visas-immigration