I'm writing an article for my blog and I want to use some funny pictures I found on the internet to emphasize a few particular points I'm making. I obtained a few from photos.com when I could, but for a few others I do not have that option. Can I source the photos or do I need permission from the content owners to even use them at all? Do I put the main website under the photo itself or the actual web link?

Anyway, it's my first blog and I'm a bit inexperienced. Thanks for the help.