Are you looking for images from others that you can use in your website? You want to make sure that you are allowed to repost any images you use. Probably the simplest way to do so is to search for Creative Commons (cc) licensed photos.
Flickr’s advanced search allows you to search only for cc licensed photos.
Flickr’s advanced search allows you to narrow your searches to only yield results that are cc licensed (see image to left).
Here’s an example of a very useful such search: for textures.
Many Flickr users go out and capture various photos of interesting textures, then upload them under cc licenses. These photos are really useful for backgrounds on websites, in layers for photo processing, and in other ways.
When you view individual photos returned via this search, you can right-click on the image and view the specific terms of the cc license (see image to right). If you click on the “some rights reserved” link, it will tell you specifically which of the 6 levels of cc license apply to this specific image. You can also choose to download the photo and at what size (in the example to the right, you can choose to download the image in two different medium sizes, 500×500 or 640×640 pixels, in large 1024×1024, or at the original resolution uploaded, in this case 4782×4782 pixels).
Finding images with Google is very similar to the process described above using Flickr.
Google also has an advanced image search, which allows you to narrow your search for only images with certain usage rights.
Here’s an example of a Google image search for textures that are available for reuse. When you perform a similar such search you’ll get a page full of results. When you click on a thumbnail, it will bring up a preview page for that photo. If you’re going to use it, you should go to the original page the image is from to confirm that you can use the image and in your attribution you should link to that original page, not just to the Google image search results page.