There are many ways that a photographer can edit images from slight adjustments in brightness in almost any editing program to more advanced edits in Lightroom and Photoshop. Even within advanced programs there are a number of plug-ins, actions, templates, Presets, ect.. that can aid in your workflow.
One very easy adjustment in Photoshop involves gradient maps.
Once you load you primary image, choose Layer..New adjustment layer...Gradient map.
The gradient map will affect your shadows, mid-tones, and highlights. In the example above, the initial window that opens converted the shadows to a shade less that pure black and gradually moved to the highlights to which it applied a much much lighter shade of black. If you double click the gradient, a second box will open as shown above. Here you have many more options from which to choose.