Arttoday Online is the world's largest image site. It is not free, and costs 29.95, but this collection contains over 1 million graphics. I've seen many webmasters use there images, and it certainally is well priced. You'll find sample images on the order page.

KPT - Kai's Power Tools V5.0 for Mac/ Win

A great set of filters which any designer would find useful. Filters include texturerizer, spheroid, and many more.

Adobe Photoshop v5.5 Windows with Imageready v2.0

Adobe Photoshop 5 is an essintial product. Few websites have become succesful without this product. It makes amazing graphics. It takes time to learn, but its well worth it. All the graphics you see here were made in adobe Photoshop 5. Buy it, its well worth it. Although it may seem expensive it pays off. People are looking for good Photoshop 5 users.        

Adobe Illustrator is an excellent program made by a company with a history of making some of the best image editing software. This software is a must for creating interfaces, and web graphics. You'll need this along side adobe photoshop.

  I must say this is the first program I used to make images. Paint Shop Pro has one of the smallest learning curves. You can pick up this software, install it, and make professional graphics within minutes.