After the close of escrow, non-U.S. residents will need to apply for a U.S. ITIN (“Individual Taxpayer Identification Number”) by submitting a Form W7 to the IRS. The form is generally submitted with the tax return that reports the sale.
Whether filing the W7 in advance or with the tax return, non-US residents are required to submit a certified copy of their passport. The easiest certification is to present yourself in person (by appointment), with your passport, at a US IRS Taxpayer Assistance Center (the closest to Casa Grande is in Mesa). Or, you can get a certified copy of your passport from your issuing agency (for Canadians, this would be a Canadian consulate).
The W7 form, and its filing instructions, are available on irs.gov for further reference.