Okay, look at the bottom of this thread for a bunch of links to what you're requiring it's been discussed before. However, in short: The best site I've found on the net would have to be: www.sxc.hu (100% free)
Yikes, no it's not a good place to take art at all. They are ALL copyrighted to the owner.. using photographs from there would be copyright infringement .
there's also stockvault.net if you're still looking though sxc.hu is by far the best as far as free stock photography sites is concerned. also maybe browse flickr and if you find one that you like send the owner a message and ask for permission. most of the time they'll agree or ask for a small fee maybe.
I'm a member of deviantart and I haven't seen any owners who have stated that people can take their artwork and use it for their own purposes... but if there are any... then.. good...
I like to use Flickr. Be sure to check the licensees. They range from copyrighted to do whatever you want, but a lot of the photo's are artsy and can add a nice flair to a site.
Some people writes that you can use their photo (or whatever) that they taken, if you show where you used it, or asks for permission
Honestly, in most cases it is easier and cheaper to purchase Royalty free images from dreamstime, bigstockphoto, istockphoto or any other micro-stock agency for $1-5 per image. At least this way you know you are allowed to use the image and the terms of use all up front - no hassle!
I am a deviantART member and trust me that is one place you don't wanna take your pictures from. If you will get reported they will get you in trouble. I joined this group once on deviantart and they update news on this topic. I got my own list if I want free images otherwise i take them myself. http://barodian.wordpress.com/resources/ Code (markup):