Here is a tutorial where I took a picture of my nephew's face and removed most of his freckles. Please remember that if you ask 100 people how to do this job, you might get 100 different ways to do it. That's just the nature of Photoshop. This was done using CS4 but should work on most other versions. Please excuse the amateur quality of my work as I am quite the amateur but also quite the enthusiast. The tutorial uses layers, filters (blur), layer masks and adjustment layers (levels and curves)