IMHO the first use of software should be to correct mistakes - in fact whenever you take data from a camera and convert it to an image we're looking at the software is already carrying out adjustments and corrections, so adding in your own knowledge of what the scene was actually like (or how you want to represent it) is perfectly reasonable.
The nice thing about tools like lightroom is they allow you to just correct the mistakes, without affecting the rest. So if you blow the highlights on a building, you can use the recovery slider to just adjust highlight brightness without changing the rest of the image for example. Likewise LR has some great croping/rotating tools.
But as far as colours go, aside from when the camera has picked the wrong white balance, there's not a lot you probably need to do, again, think 'correction' rather than 'enhancing', as a starting point at least.