This is really a basic "how do I do post processing" question, and it's beyond this group to do general tutorials of any length. I've linked to a couple of older questions with some links to some good resources and discussion on this topic.
That said, the general answer to your question is that you don't need any specific button or slider in Photoshop or Lightroom to process an image, because there are usually a dozen ways to get the look you want and you can get through to the look you want.
In older versions of Lightroom I was taught not to use the contrast slider and to use the tone curves. In current (LR 5) I've flipped around and I almost never use the tone curves any more in favor of other techniques, but I'm adjusting contrast on most images. It comes down to learning your tool, having a vision for the way you want an image to look, and putting enough practice into post processing to be able to manipulate the image to get to that look.
There is no "one way" to process an image, and there's no "one look" that's correct. What matters is your look. And more importantly, there's no magic formula to process images, there are lots and lots of them -- and you need to put enough time into learning enough post processing to understand which path you're comfortable with so you can produce good looking images in the way you like reliably and efficiently.