For many of us, the digital darkroom remains an intimidating place. There are so many tools, and so much power and so much apparent complexity, that many image makers are content with the JPEG that the camera spits out.
Nothing wrong with that. You paid good money for your camera and its designed to make the experience simple and positive for you. In fact so many people are into photography these days there are literally hundreds of simple post processing apps to get to good enough very fast.
The full story is that the digital darkroom brings us more capability, more simply and with less toxicity than the chemical darkroom ever did. And if you are concerned about wrecking your images, heres what to do.
Instead of importing, ingesting or whatever term your software uses to get the images into itself,directly from the card, copy them from the card to a hard disk first. These are your master originals and you wont work on them at all. Once done, now do the import process into your editor of choice. Some editors have catalogues like Lightroom and iPhoto. Others dont, they work directly on the file itself such as Bridge to Photoshop. I prefer proper catalogues, but they are your images, do whatever you want, just only work on copies of the originals.
Editing can be destructive, such as when working on the Background layer in Photoshop, or non-destructive, such as anything you do in Lightroom. Because you are never working on your master original, this doesnt matter.
In any case, nothing you do in these editing tools is permanent until you commit the change, and even then our good friend Mr. Undo can get us out of all kinds of trouble. He has two aliases Ctrl-Z on the PC and Cmd-Z on the Mac. He is your friend.
You can take public courses, online courses, watch Youtube videos for the rest of your life or even hire <insert plug for self here> a private coach. Whatever works for you. But, and this is critical, remember that the source may have a different desired outcome than you do. If the source is a paid professional photographer, experimentation is not on their radar. They are about speed and throughput. If you are a happy amateur, and even if you sell some work, you just may not be in that big a hurry. Take your time.
Now once in the editor be aggressive. Push the sliders to their stops and watch what happens. A lot of the time things will look like crap, but only by pushing the envelope of each slider do you start to see what the slider can do. Once you are comfortable with one slider, make notes on what it does. Your memory is not perfect and there are hundreds of things to play with.
Learn each slider individually before you start stacking things up. Every educator has a preferred working order. Copy one that makes sense, but alter it if it helps you make a workflow that works for you. Your goal is to get to the point where you can look at an image, see a single change you want, and know which slider to go to and where you might want to start with the adjustment. You wont need 20 applications. If you actually do this, you will be astounded by what you can do with the things you already own.
Experimentation will take some time. Its also a huge amount of fun, and always remember, you arent ruining anything because you always have your untouched originals.