If you know photoshop already and are looking for step by step, Model Mayem has some good ones and retouchpro.com is a great resource as well. If you are looking for actions, do a google search for the type of action. They are out there, you just have to look a bit.
For skin editing, I would recommend Lee Varis' book called "Skin" there is a lot of info on retouching skin, I use a modified version of his techniques.
Although it is not a technique forum, I would suggest http://photography-on-the.net
. it is a great site for ideas, inspiration and if you search, you can find a lot of posts on skin softening.