A picture is worth thousand words. Right picture can entice your readers into reading a particular blog post.
These are the places where you can find free images for a blog post or for your website.
1. Flick Creative Commons: I use Flickr for all my blog posts on my blog. Facebook is where highest number of photos are shared, Flickr is next. Good things about Flickr that it offers a creative commons section. Images under this license can be freely used in blog posts after due credit is given. A search for keywords entrepreneur in following results.
2. Dreamstime Free Photos It has a collection of more than 200,000 free images and one can download and use these images under Limited Royalty Free License (RF-LL). Search resulst for word “entrepreneur” are here.
On Flickr you may have to do a through search for your photograph but it will give you more natural results. A stock photo site like Dreamstime will give your more professional looking photos shot using models. You need to see which of these suits your purpose.
If you are a graphic designer or marketer who needs to choose images for a particular campaign then check out Shutterstock, iStockphoto, and Fotolia. These are some of the biggest players offering royalty free stock images. Another major site is stock.xchng which is now owned by Getty Images.
Getty Images is a premium service and offers a much wider selection which comes at a premium.
Also check CompFight, a search engine for images.
Update: MorgueFile, I have yet to check it in detail but attribution is not required for any images that you use. On initial exploration I found many options for an image search.
Update2: Check Ookaboo.
Update3: Photopin, free photos for bloggers. (hat tip: Sachit Gupta) [On Jan 5, 2012]
The image used above free courtesy Flickr user Rob Jewitt.