Join Taz Tally for an in-depth discussion in this video Using the exercise files, part of Photoshop Color Correction: Target-Based Corrections.
If you are a premium member of lynda.com, you have access to the exercise files used throughout this title. You'll want to download the exercise files folder to your desktop for easy access. And then, all you need to do is double click on this folder to access the files inside. For this particular project, you'll see there's only one starting file. And that you'll open that up inside of Photoshop, to begin your correction. If you are not a premium subscriber to lynda.com, you don't have access to the exercise files, but you can follow along from scratch with your own assets.