I started photography in a hard way where there were not many place you can go and learn it from taking picture to post processing then end product. Here is a good video tutorial on learning how to use photoshop.
It's a set of 20 over-the-shoulder screencast tutorials, where professional Portrait Photographer John Silks shows you step-by-step how he processes his images. He covers the key Photoshop tools and how to use them, the essential fixes & corrections, and all the special tweaks that make his Clients so happy with the final result!
There's over 2 hours of valuable training, all broken down into simple bite-sized chunks so you can watch-do-learn any processing task you need, as you need it.
