This has been requested by several people, and it never actually occurred to me that indeed I have developed a certain process in finding great photographs for my blog and have finessed it over the last year, but didn't think it would be worthy to blog about. But now that I do think about it, it is worthy of a blog post, because it involves copyright issues, and other things that are often ignored, because it's very easy to just Google an image and post it on your blog. My position on this is, a photograph is a work of art, it's the same treasure to that photographer as my novel is to me. I have to treat it with respect, I have to treat the artist with respect, the same way I would like someone else to treat me and my art. It's an intellectual property. So I have developed a certain procedure as to how acquire the photographs, from whom, where, and how often. Here is what I do.

All of my blog images come from Flickr. I've been on many different sites, but I keep coming back to Flickr simply because it's the best place where semi-professional and professional photographers post their work. When I write a blog post, I typically search for an image that has a similar theme to what I'm writing about. There are three things to take into consideration:

Search. Let's take the word raven for example. When you type in raven in the search box on the top right, when you see results, look at the top left corner, you will see that you can sort the images by Relevant, Recent, or Interesting. Select Interesting and see the difference in the images you get. Amazingly different pictures of ravens, right? Now, scroll around to find an image you like. I only look at images at the Interesting category.
Copyright. The method I have described above shows you all of the Flickr images, and most of those will say All Rights Reserved next to them. That means without specific permission from the artist you can't use the images. I always write a message to the photographer first, asking for permission to use the image on my blog. Or, if I'm in a hurry, I ask for permission after I published my blog (and I tell them that I'm a bad girl and if they will forgive me), with the full intent of taking down the image if the photographer asks me to. In 1 year of me doing it, it only happened once.
Creative Commons license. If you don't want to trouble yourself with contacting photographers, then this is a choice for you. Just go here, select Flickr, and type in raven in the search window (don't forget to uncheck use for commercial purposes box) - voila! These images you can use without asking for permission, you can modify them, cut them, do anything you want. You will see, however, that the quality of images falls significantly. I used to search for my images this way, but not anymore.

I develop relationships with photographers. Most of the images you see on my blog are done by the same small handful of photographers with whom I have exchanged a few emails and who have given me permission to use their art repeatedly. Here is my list of contacts, if you want to take a peek. I also always give them credit, in my blog as well as on Twitter, Facebook, Google+ or any other social media channel, if I want to post their image alone. You've seen me do it, probably, and you have probably noticed that I always credit the artist (unless they have given me permission to not do it). This is important, because it builds trust. Photographers are those people who have been burned so many times online (it's so easy to steal their work), that they are extra sensitive to anyone who is trying to use their art without their permission. Once they see that you are cool and mean no harm, they simply love you for it. Especially if you credit them, because not everyone does. So, what I do is, once I find an image that I really love, I go and look at the Flickr photostream of that photographer, and I select the photographs that I liked as my Favorites, to use later. If the photographer gave me permission, then I use those images later. Here is my Favorites list.

I subscribe to a newsletter to get updates on new work. Because I have an account on Flickr, and after I have used a few photographs by a certain photographer, I add them to my contact list (the one I mentioned above). Every week I get an email with updates from my contact list, so that if the photographers whom I added as contacts did any new work, it will be in that digest. Effectively, I have found my group of artists and now hardly spend any time searching for images at all, because it seems like we have the same ideas that we snatch from the air, and usually I can snag a picture from the newsletter, because it fits my blog post perfectly. My favorite of all photographers (on my contact list) is Joel Robison, who loves books and frequently posts pictures with books, and I use his images a lot, as you have noticed. I suggest you employ a similar process and find your favorites, or reach out to mine. Either way, it will take you time to build your own database. It took me close to 3 months to find most of my contacts, and I love their work, so it's easy for me to pick our images now, takes 10-15 minutes, where as before it would take me up to 3 hours sometimes. I know, I'm a perfectionist, but I wanted my blog posts to look beautiful!

Things to watch out for. There are a few things that should be red flags for you, when selecting a photographer to work with, not because somehow the photographer is not very good, no, but because of the process I have described above, and because of how touchy feely some of them are, which you have to respect and step aside.

If you see a watermark on the image, or a signature, or a name, any kind of sign that the photographer has put on her or his picture, don't even bother contacting them. Those who do this are very protective of their work and they will tell you no, even if you're only wanting to use their image for a blog post.
If don't see a lot of consistency to the images of a photographer whose one or two images you liked, then you have stumbled on someone who is doing it just for hobby, and will likely not steadily producing good work, only cluttering your email inbox. Look for consistency and rate of production.
If the photographer doesn't answer your message for a long time, don't use them. They might be either not interested, or don't want to deal with you, or unsure, or too busy. This doesn't mean that you can go ahead and use their images by default. Don't.

In general, my mantra is, beautiful stories have to be illustrated by beautiful images, that's why I go out of my way to find amazing photographs for my blog post. Partially, because I'm a photography junkie, but partially because I believe that a beautiful image sets a background for the story, much in the same way we pick out a book based on its cover. In this sense, I believe that the image is the first thing that will grab my reader's attention, therefore, it must be chosen carefully, much in the same way words are chosen carefully, to make an impact. There. I think this is it. Well, was this helpful? Is this what you were looking for? If you have any questions, fire away in the comments.