Graphics make a great draw for your site. However, finding good graphics to use can sometimes be a problem. If you've taken a photo yourself or created some graphics, you can use them with abandon because they are yours. You own the copyright automatically.
That's the crux of the issue: copyright. If you are serious about your business, you do not want to have anyone coming after you for copyright violations. So, if you have not taken the photos or created the graphics yourself, what do you do?
If you plan to use the graphic long term, the best thing to do is to purchase some royalty free photos or graphics. Royalty is something you pay monthly or annually for the use of some copyrighted material. Royalty free means that you purchase the rights upfront and do not have to pay royalties. But do not let the thought of the cost scare you off from looking at this. Depending on where you go for these graphics, the cost can be as little as a few dollars.
Awwhile back, SmashingHub.com put up an article, "25 Best Website Resources of Free Photograph Stock Photos," which has links to these resources. I've used the first one, Stock.xchange, for quite some time. Most of the rest were new to me. You can probably find completely free graphics to use on these sites as most have tons of free ones. But occasionally you'll see one for sale that is exactly what you need. If so, put out a few bucks to get it. Then you'll own the rights to use it for as long as you want and in just about any way you want. (Always check the fine print.)
Frustrated about the copyright issues? Do you feel that you should be able to use anything you find on the web without considering that? Think again. There is a whole field in the law profession that deals specifically with internet law. But think also about the photos you have taken or graphics you have created. As I said above, you automatically own the copyright to those. Would you want just anyone to have the right to drop by your site and use them without notifying you? This law cuts both ways. It not only protects the other guy, it protects you as well.
So, get creative on your own or use someone else's work. Either way, be sure to respect copyright issues.