In this tutorial, I will show you how to make everything in an image black and white accept a few items. Here is an example.
Step 1. Open the image of your choice.
Step 2. Duplicate the background layer. You can do this by dragging the layer on top of the new layer icon in your layer pallet menu or under the layer menu click duplicate layer.
Step 3. Add a layer mask to the background copy layer and fill it with black.
Step 4. Using the tool of your choice, select the area you want to remain in color. I used the magic wand tool just because I am not looking for precision. Click on your layer mask an switch the paint to white. Using the paint bucket tool fill the selection in with white on the mask.
Step 5. Unlock the background layer by double clicking on it. Then desaturate the background layer shift + apple+ u (apple) or shift + control + u (windows) or under image -> adjustments -> desaturate.