Photos make a positive impact on websites, charts, slide presentations, and other visual materials. If you throw some text and colors alone, it can be pretty, but if you add beautiful stock photos, the final result is many times better.
One option is to buy photos from sites like shutterstock.com: they provide great photos, videos, cliparts and more. But there are plenty resources to find free stock photos as well. Here is a curated list of best free stock photos resources: