I'm a Dual Citizen of Mexico and Canada. Canada has agreements with 25 countries that allow you to work for a year in a foreign country for one year if you are under 35:
As for only knowing English, well, it depends on the industry. Most companies want to tackle the US market and they would see your native English as a very good asset. But you would need to bring something else to the table (good chops or connections, basically).
http://www.international.gc.ca/iyp-pij/agreements_in-accords...
I'm not sure about US agreements with other countries, but I know that if you have a university degree of the following list http://www.u-s-a-immigration.com/INS/NAFTA_Professional_Job_... then you are allowed to work in Mexico and Canada.
As for only knowing English, well, it depends on the industry. Most companies want to tackle the US market and they would see your native English as a very good asset. But you would need to bring something else to the table (good chops or connections, basically).