If you want to try Forensically: http://29a.ch/photo-forensics/
This is a tutorial on how to use forensically. A set of free web based tools for photo forensics. It shows you how to use Clone Detection, Error Level Analysis, Meta Data (exif) analysis, GPS location and Thumbnail analysis. You will learn how to use these tools to detect photoshopped or otherwise forged images.
I'm sorry for the audio quality and breathing into the microphone. I'll try to do better next time. I hope you still find it useful :)
