Open Question: US/Canada Tax return question?

A little bit of background... I am a Canadian citizen, and have been lving back in Canada since September of 2008. Under IRS laws, since I also hold a green card, I am a resident of the USA for tax purposes. This year I will be filing both a USA and Canada Tax Return, which I have an appointment to do next week. Here is my question... In Canada for 2009 my wages were approximately 13,000 I also received approximately 9000 in spousal support from my ex husband, who lives in the USA and is a citizen there. I only paid approximately 200 in taxes on my Canadian income, (deducted from my pay) and have paid no taxes on the spousal support. I am filing as head of household, as I have a 4 year old daughter. I also purchased a house in Canada (first time home buyer) in 2008 Does anyone have a clue at an approximate amount I will be paying in taxes? I am aware of the foreign tax credit. I'm just a little worried that I am going to have to pay a lot of taxes this year, although I am barely making it as is! Any help would be appreciated!