Golden rules:
1) respect there copyright on pictures
2) always ask the photographer for permission to use the picture
3) only the photographer can give you permission to use the picture
4) make clear agreements about the use of pictures, licenses and fees
5) only use the picture in situations agreed
6) always try to find the photographer
7) always name the photographer (photo credits)
8) do NOT edit the picture without consent
9) keep in mind that besides the photographer third parties might have rights on a picture as well
10) always offer the photographer a publication proof
