Firstly, you can look at the title or the description below the image to get clues!
The image mostly is the puzzle so examine it closely!
You can also view information in the source by just two keys (ctrl + u)!
Some levels require you to manipulate images like cropping or adjusting brightness and exposure.
And you sometimes need to change the extension/name of the image too!
If you don't know any information in a level, search Google to help!
Whatever you do, don't give up! Try again or grab a friend to help you.
That's all! Go and solve this level now!