It's an older post - but the problem is still a real-world issue.
A couple of things I can add: When I first created a website, I needed some images. Most were ones we'd taken ourselves but a few we found by searching on Google for a suitable phrase or whatever and then selecting 'Images'.
On that set of results, directly below the search bar, is a set of options for size, colour, type and - importantly - usage rights (if this set of options isn't displayed, click 'Tools' near the search bar and it should appear).
When you drop down the usage option, you should be able to select from a list, one of which is 'Creative Common' and this will filter images that you're allowed to use providing you adhere to the rules! Some will be 'credit the owner' only, some will require a small payment and so on. Some will allow you to modify the image/s, others you can't alter. Just find a few you think will work for you and go through them, checking the options. Quite often, all that's required is a line on the same page as the image that says something like 'with thanks to JoeBloggs (weblink) for the image of the cat' or whatever.
On a second note, if you are chased for copyright violation, do check that it's a real claim: In the distant past, I got a letter telling me I'd abused an image from some place or other and owed them a fantastic sum of money. When I checked the image reference, it was quite clearly one of my own (it was a photography website and I was showcasing my own work, naturally). If I remember, the address they claimed to be operating from was the HQ of the Welcome Trust in London! Confident that I was on safe ground, I ignored them. That was a very long time ago and I didn't hear another thing from them ever again - but don't assume they're all fake.
Make sure the images you display are ones you've got permission to use, acknowledges the copyright holder or that you have paid any fees due. Someone, somewhere has put time and effort into creating the image and it's only fair for them to expect recognition - especially if you're using it to enhance the value of your website.
If you already have a website with images and need to go back to check where you got your pictures from, TinEye or Google's own reverse image search function might help you find the original to check any usage rights. Don't assume that an image with no rights displayed means you can use it however you want, though.