To enter Canada you will need to carry proof of citizenship such as a passport, birth certificate, a certificate of citizenship or naturalization, a U.S. Permanent Resident Card, or a Certificate of Indian Status along with photo identification.
The Canada Border Services Agency's webpage gives you all of the information you need to know about entering Cananda
(click here)You also need to come back across the border and you will be playing by different rules. You will need a valid passport or passport card to get back into the United States.
The rules for entering the U.S can be found on the U.S. Custom and Border Protection Service website.
(click here)You can get passport information on the U.S. State Department's Passport website.
(Click here)If you don't think you will need a full passport, I suggest that you get a Passport card. They are good for going back and forth to Canada and Mexico. They only cost a total of $55 dollars, where as a full blown passport cost a total of $165 bucks. The application instructions are on this website.