Well here you will be taught how change the lighting of picture to make them look really cool. This is one of themore basics effects to do so you shouldn't have any trouble.
1. Open the picture that you want to add color dodge to. Then click and hold the layer and move it on to the ADD NEW LAYER button. Its the middle button one the bottom in the pic. That will make a copy of your layer.
2.Next on the new layer that you just created. Go to FILTER > BLUR > MOTION BLUR. You want to blur the picture alot, but not too much. Around 75-150 is a good amount.
3. After you have motion blured the picture, go back the the layer window. Click the tab that says NORMAL and go down until you see Color Dodge, then click on it. Thats it.
Here is an example.
More with color dodge
Once you have set your layer to Color Dodge, go to IMAGE > ADJUST > HUE/SATURATION and there you can change its color.
More Tutorials: 
