Most computers come with a free basic program. I have Paint. It is pretty simple to use, but what you can do with it is kind of limited. I like to use it to create colored backgrounds and adding book covers or multiple images to the same graphic.
I often pair Paint and Photobucket to create my graphics. You use to be able to do more with Photobucket (see this post), but I still use it for background effects and frames. I also like some of the fonts offered. If you need a set size, I find Photobucket makes it easy,
Another photo editor that I know a number of bloggers and authors are using is PicMonkey. They offer some set canvas sizes, including Facebook cover. One of the features I miss from Photobucket is the collage function. Pickmonkey offers it and can be a great way to easily put a number of images, such as covers from a series, into one graphic.
The other day I had a Doh! moment. I was looking at some graphics made by the National Weather Service and realized they were PowerPoint slides. There are a number of open source programs that offer presentation options. I like KingSoft. I've used Open Office as well, but find it kind of buggy.
If you have a little time, it would be well spent learning the basics to PhotoShop or the open source program GIMP. They can be a little intimidating, but once you get the hang of it you can make some pretty cool graphics. Do a quick search for Photoshop tutorial or GIMP tutorial and you will find step-by-step guides and even a few YouTube videos.
In my ebook Secrets to a Successful Blog Tour, I offer my own step-by-step guide to creating tour graphics. You can get it at Amazon, Smashwords, B&N, Kobo, and iTunes.
Donna Huber is an avid reader and natural encourager. She is the blogger behind Girl Who Reads and author of the how-to manual Secrets to a Successful Blog Tour.
Girl Who Reads is an Amazon advertising affiliate; a small fee is earned when purchases are made through the links above.