http://www.roniloren.com/blog/2012/7/20/bloggers-beware-you-can-get-sued-for-using-pics-on-your-blog.html

Interesting article figured someone might get some use out of it. Apparently the lady who wrote it got sued for using pictures from google images on her blog even though she credited the source. Quick summary of the article:

Here's what I learned about Fair Use:

It DOESN'T MATTER...

if you link back to the source and list the photographer's name
if the picture is not full-sized (only thumbnail size is okay)
if you did it innocently
if your site is non-commercial and you made no money from the use of the photo
if you didn't claim the photo was yours
if you've added commentary in addition to having the pic in the post
if the picture is embedded and not saved on your server
if you have a disclaimer on your site.
if you immediately take down a pic if someone sends you a DMCA notice (you do have to take it down, but it doesn't absolve you.)

NONE OF THAT releases you from liability. You are violating copyright if you have not gotten express PERMISSION from the copyright holder OR are using pics that are public domain, creative commons, etc.