I think the most important part of web design is the photos that you use on the site. Seriously, choosing the correct photos actually makes or breaks the design, so it is extremely important to choose the right photos. Most web designers attempt to design the site based on the photos which they have. Anyway, 123RF is a relatively new site offering stock photos on the Internet. You will be able to find all sorts of photos and images on their site - they have over 9 million stock images in their database! They are subscription based as well as credit based. So if you need just one image, you can purchase credit for that image and you are done. However, if you are a web designer with a lot of projects, it would make more sense to get the subscription. They offer royalty-free high quality photos so you don't need to worry about copyright and all those stuff. And your customers will surely be impressed with your work.