You'll probably need a exif reader Opanda is quite good, i use that one, best part is its freeware. Install it, next time you view a picture on the gallery or elsewhere just right click on the pic and if the exif is in in the photo then it will be displayed.
Take note though, a lot of people uploade their photos Save for the web or in sRGB format mostly which strips out all the exif data , so don't panic if you can't always see it. It just means the person has uploaded without the exif data attached.