One of the biggest challenges of blogging is sourcing images legally, efficiently and effectively. Hopefully these resources will help you meet the challenge!
Don't fall prey to the shady practices of stock photo licensing companies. When you pluck random images from a Google search, you could be costing your business far more than any image license. Take some time to learn where to find images that you are free. Once you've got those sources you can select images that compliment your content and make it stand out visually without costing a fortune.