One thing that this tread has pointed out is that there is no one right or wrong way to approach post processing. There are multiple methods that can be used to complete any individual task.
To set the back and white points you can use Levels or if you need more precise control you can use the Double Threshold method described by Bob in post #8 or if you need even more control you can use the LCH editor as described by John in post #13.
In the end all three do basically the same thing, set the overall tonal range, the contrast, color saturation…etc. The best method to use depends on the requirements of the image you are working on and/or your comfort level in using the tools.
I have probably read about 10 different ways to approach Sharpening some more complex than others but not one of them is the one and only right way.
People often get overwhelmed with all of the differing methods when trying to learn to post processes their images. What most need to do is to learn the basics. Such as…
How to understand the histogram.
How levels and curves work and why you are adjusting them.
The difference between Capture Sharpening and Output Sharpening and when to use each.
Once you have learned the basic tool set then you can go in deeper to more complex tool sets to find what you really need to produce image that meet your needs.