Duplicate Content Penalty when changing URLs?

We need the old URL's to work for AdWords

[Donger]

Our URL's were previously built like this:

[mysite.com...]

Where "ID" is the product ID. A high level software engineer at Google informed us that Google does not like the "ID" in the URL because of session ID reasons. The engineer suggested changing the URLs to something like this.

[mysite.com...]

We made the change, so all the links on our site use the new format. But we need the old URLs to continue landing since thousands of AdWords ads link to the old URLs. But we don't want a duplicate content penalty.

What should we do? Should we use 301 redirects from all the old URLs to the new URLs? Will that tick off any of the other engines? Any advice would be appreciated!