I'm a Canadian traveling from Toronto To Warsaw and I have connecting flights in New Jersey and Frankfurt. Will I need an ESTA or a Transit Visa?
Good news - as a Canadian citizen, you're a member of one of the few groups that don't need visas for the US.
From the Canadian Embassy website:
Note: ESTA is not required for citizens of Canada.
On 12 January 2009, the Department of Homeland Security (DHS) introduced ESTA, the Electronic System for Travel Authorization. This online system is part of the Visa Waiver Program (VWP), and all nationals or citizens of VWP countries -- excluding Canada -- who plan to travel to the United States for 90 days or less for temporary business or pleasure under the VWP need to receive an electronic travel authorization prior to boarding a U.S.-bound airplane or cruise ship.
So you'll be fine travelling through the US on the way to Germany! Enjoy your trip.
The US government has a page for Canadian citizens. It says:
with a few exceptions that probably don't apply to you.