Playing with Photoshop

I've decided that I want to learn more about how to tweek pictures in Photoshop. I am using PS CS3 and am going to toss pictures up here as I experiment. Feel free to comment. Constructively please.

The picture on the left, in color is the original. My daughter in a cute cotton nighty on our balcony waiting for her dad to get home from work during our stay in Paris.  In the middle is a simple photoshop conversion to b/w. On the right is a combo of the two. I extracted the nighty and placed it over for a hint of color.