Mastering contrast: Shadows/Highlights
You'll note that under the Enhance>Adjust Lighting menu, there are two other tools worth mentioning: Brightness/Contrast and Shadows/Highlights.
The former does exactly what Levels does, but without the benefit of being able to see that tone mountain, which for most photographers is enough encouragement not to use this feature. It's also regarded as being a destructive form of editing—too much use might damage the pixels irreparably, so I'd not recommend using it.