It really depends on how well your photography looks to begin with and what kinds of effects you want on your photos. I have always been against most post editing. I do use picasa for most of what I need and I do use corel for noise removal and when I want to have fun playing around with my photos. You can use post production to fix photos or make them look different.
It depends on what you want to do with your photo. I have always chose to work my taking better photos than fixing them later. But you can do some really cool things with photoshop.