I want to make some extra cash making people posters for a small fee. I wondered if Google Images photos can be used without paying anything. I assume I at least have to give the url under the photo, but I want to know the specifics of what can and cannot be done.

Copyright laws are there for a purpose and you may appear to be a stalker.

you will have to go to the actual source of the photo, Google merely is a search engine for locating photos from other web sites. So many of the photos have copyright protection.

I took 10 random photos, and followed them back to their source. All where from copyrighted webpages.

So you would need to find photos, and track them, and find ones from pages not protected under copyright.

Can photos found on Google Images be used commercially? - Generally, NO, as already mentioned.

Fair use doctrine states that you cannot use copyrighted material to earn income from any product using that material.

All right! Thanks, folks.