Whether you're blogging or writing novels, pictures can be very useful. (In the case of fiction-writing, a photo of a place can help you get the feel of it.) But where can you obtain good pictures without ending up on the wrong side of copyright law?
Here are the five options I choose.
Take your own
If you have a smartphone then you already have a camera with you wherever you go. I'm a bit old-school: I think you can get better results from a camera, because you can exercise more control over the settings. Most of the time I carry a compact camera just in case I spot something interesting that I think I might be able to use one of these days.
Use the creative commons search engine
Files with certain kinds of Creative Commons (CC) licence are usable without running into legal problems -- as long as you abide by the terms of the licence. For example, it may allow you to use the file for commercial purposes as long as you cite the source. The most user-friendly kind of licence is CC0 (that's a zero), because that allows you to use the file for anything you like without even saying where it comes from (although I think that's the polite thing to do). Even there, though, check the terms of the licence because you probably won't be allowed to sell or give away the file itself. For example, you may be able to use a photo in a blog post, but not just stick the photo on your website and say "Come and get it".
When I use the CC search engine to look for photos, I tell it to search on Flickr, because I've found that that is where I get the best results.
RGB Stock photos
This website has thousands of high quality images. Well, high enough for use on a blog or website: high resolution images cost a small amount of money. Definitely worth a look, especially as the site's search engine is pretty good.
The other 7
I recently came across an article entitled Where to Find Free Images Online to Use in Blogging & Social Media, by @EdieMelson. This lists 7 sites where you can obtain free-to-use photos. Some of them see very good, but I haven't used them enough to be able to recommend them yet. But di check them out.
One thing I would definitely caution against is just searching Google Images and grabbing one without checking the licence. I've found that quite often they are not free to use at all. Google does point this out, but I thought I would too.
Picture credit: This photo has a CC0 licence, and comes from splitshire.com