First thing, dont get discouraged by all the words. I learned pp for photos by reading on here at DPS. There are many who use different softwares liek GIMP, Elements, Lightroom, and PS.
SOOC shots are not always perfect, especially when you are starting out. Different styles of photography like people shots, product photography, landscape photography, etc. require different kinds of pp. No matter what app you use, you'll always find some method. It all depends what you want to go for.
Here is a pp method I use for portraits inspired by Amy-Rose
http://amyrosesecretsrevealed.blogspot.com/
There are tons of others. In fast DPS has a good collection of tutorials on the blog. Just need to do some digging.
Feel free to IM me if you have specific questions.