Navigating the US tax system can be rather daunting, and the penalties for innocent errors are far higher than seems reasonable. As someone accustomed to the relative ease and helpfulness of the CRA, stepping into IRS territory is enough to make me want to curl up into the fetal position.
But the good news is that there is a minimum threshold for filing taxes. If you are single and making under $9,350, you are not required to file. You can see the other reporting thresholds for 2010 on this page of the IRS website.
Remember that all figures are in US dollars, as calculated based on the end-of-year exchange rates posted on the US Treasury Department’s website. The site is frequently down, but keep trying and you’ll eventually get through.