I'm looking to add some design elements to my site. Not photographs but something more simple. Where's a good resource for this on the web?

A lot of the sites that offer stock photographs also offer stock backgrounds and other graphic elements. You could do some research for digital scrapbooking elements too. So much depends on what kind of site the images are to be used on.
What kind of things did you have in mind?

Kristi

Here are links to two of them you can have a look at:

http://www.istockphoto.com/

http://www.123rf.com/

A free website I use a lot is:

http://www.openclipart.org/

CoffeeCup has a graphics pack as well.

Thanks for the share there Eric, nice image site that I haven't seen before

Janys, I'm looking for professional, modern type elements.

Here's another one to check out
Search under illustrations, clip art or design elements:

http://www.dreamstime.com

Kristi... are you absolutely certain they are not the kind of things you could do yourself with an image editor? Simple is often best in my opinion, and even the less expensive (and free like Gimp) editors have usually got a few slick, lean examples to follow. Just a straight bar of colour can normally have drop shadows, metallic, glass, textured effects added with the minimal of effort and experience.
Are you wanting to add them to the metal work site? (If I remember rightly - forgive me if my memory if wrong).

There is so much open source these days, that anytime I search for something new, I almost always see if there is open source first.

You just have to read the fine print. Lot's of image sites and sites that offer free software stipulate that is is for personal use only. If you want to use it for business, you have to pay.