You can search for images at stock photo sites. Do a google search for "stock photo", and you will find many such sites. Some offer free images, while others require you to pay for the images you use. Searching for images in google is tricky. Strictly speaking, images are copyrighted unless otherwise stated; it's a copyright infringement to use an image found through google without the owner's permission. But image stealing on the Internet is rampant and the chances of you getting sued are extremely low.
If you're using WordPress then the Zemanta plugin is an excellent way to get copyright-free images quickly.
i am searching in Google images then use it for my blog. I sometimes edit the image, out the address of my site on it before posting on my blog. I sometimes gives credit to the real owner of the image. It is better if you'll optimize your image too.
istockphoto.com - millions of web-sized images for just a buck or two each, fully licensed, royalty -free
I draw images on my own. You can check out my blog. I don't wish to invest money for an image evrtime I post a new thread. At the same time, free images may not be that appealing to many.
One problem I have found with Zemanta is that is not compatible with some themes, but it has been shown that simple, plain themes usually generate higher clickthrough rates.
This is not true. Most of them are free to view, but unless you obtain them from a copyright-free source you are liable to get into trouble if you steal them.
Give the Zemanta plugin a try. It will save you much time as it finds the images for you. Even more important, if byline attribution is required for the images it finds, it automatically adds it for you.
I prefer Dreamstime.com. They have big commercial image database with quality and properly sorted images in various categories and collections. They also have one of the biggest free images section, with free images that can be used also commercially (with just few restrictions). I am also satisfied with them from the point of view of photographer (image seller).
http://stockphotobase.com Not gonna lie. It's my stock photography database but we charge just $100 for one year's membership which entitles you to UNLIMITED DOWNLOADS. You can also buy individual photos as a free member for $1.50 We only have a few hundred photos at the moment but are BRAND SPANKING new but are adding 50 or so a day and we anticipate having nearly 1000 within a week. We also offer a 'Request an Image' service if you are looking for something specific. Let me know. Register here: http://stockphotobase.com/register/