Your graphic or web designer should be able to source good value for money images for you, so always ask them for advice.
There are several free image websites out there along with some good low-cost options.
I can recommend you take a look at:
- Free Digital Photos.net
- FlickR (make sure you have the right permissions under the Creative Commons Licence)
- iStock Photo
- Big Stock Photo
- Image Chef
A note of warning about free and low-cost images…
iStock is very heavily used, so your image will not be unique to your brand or business (if this is a major concern you’ll need a less popular source or to commission your own photography). However, with careful editing and your own ‘branding’ by your website/graphic designer you can create a differentiated look for your business. My website, for example, uses images from iStock in the website and blog headers.
Just something to bear in mind and also the images can be a bit cheesy and Americanised for a UK audience.
Remember that you must have royalty-free images and you cannot simply copy any image you find online as it will most likely be copyrighted to the original photographer or artist. Misuse could get you into legal trouble!
Happy photo hunting!