Google has released the following four Google+ hangouts discussing Google Shopping. The first is an intro and overview. The second is an intro to the Merchant Center. The third is about creative and optimizing product listing ads, and the fourth is about Google Trusted Stores and setup.
Google recently shared this Google I/O session video about "empowering local shopping" with Google Shopping as well:
If you take the time to watch all of these, you should be pretty informed about the Google Shopping process.
Remember, Google will complete the transition from Product Search to Google Shopping this fall, and it's already August.