It has been quite some time since I wrote anything here because of significantly increased time demands from other things. Today, I find myself here inspired by Matt Kloskowski's month-long project of posting a picture a day edited only using Lightroom. Those who know me (photographically) know that I use Lightroom extensively, and as my primary post-processing tool. I believe it to be excellent for ingesting, cataloging, developing, and displaying my images. YMMV, but that is not the point of this post.
My point here is that there are two components to being able to "properly" develop a photograph, no matter the technology you are using. First is the artistic vision to know what you intend the outcome to be. Whether it is palatable to others is a completely different discussion, albeit an important one. But the fact of the matter is that you have to have an understanding of what you would like to have your photograph look like when you are finished manipulating it; some would say you should know this when you press the shutter button. What "general" fixes you want to make, as well as specific details like lightening only a face or bringing out details in a distant mountain help to make your pictures stand out. Those artistic decisions will, in turn, determine the tools you need to do the job. I have been using Lightroom for about 95% of my work for the past five years, though Photoshop, NIK software, Paint, ProShow, Noise Ninja, Pano Tools, Photomatix, Helicon Focus, DPP, and more occasionally make it into my workflow. Each tool has a specific task to help achieve my vision.
The other part of the formula is the technical mastery of the tools you are using. Back in the darkroom days, we had to know chemicals, papers, timings, etc. If you are still working with film, that technical knowledge is still required. If you have migrated to the digital age, the tools to accomplish the job have changed, and you need to know your way around the "digital darkroom." Just as technical knowledge is required at the time of image capture to determine shutter speed, f-stop, and ISO to make proper exposure, so it will be required when you finish working out the details in post-processing. It is not enough to know what contrast, tonality, and coloring you desire others to see, you now have to know how to make that happen.
Both of these skills take time to develop (pun intended!). That means we need to practice developing photographs just as we need to practice capturing the image! Just as most photographers will tell you that great photos do not depend on the brand of camera used to make them, so too your choice in software for post-processing. Choices have consequences in your capabilities, but there are many products that are available these days. Aperture, Lightroom, and Photoshop Elements are going to be the basics recommended by most people. Choose one and learn it the same way you learned your camera. Once you have mastered one, try something new ... the skills you learned will transfer even if the details are a little different.
If you want to see what is possible using only Lightroom, take a look at Matt's website http://lightroomkillertips.com/ and scroll through the "Lightroom Only Month."