Question: I have employment income from two provinces during 2008, should I file two tax return files for each of the province?
Your province of residence is the province where you have the most significant residential ties. For example, if you have your principal residence, bank accounts, children and spouse in Alberta on December 31st, you are a resident of Alberta and file an Alberta income tax return regardless of what province you worked in. Even if your family lived temporarily in another province the residency is based on the province you had the most significant residential ties.
I would suggest you take a look at the CRA’s document called Determination of an Individual’s Residence Status. While this document discusses residency of Canada versus another country, the overall rules also apply to provincial residency.
If at any time you lived in Quebec but worked in another province, you will need to request a tax transfer to Quebec because Quebec requires its residence to file a separate provincial income tax return.