Well, I spent a long time looking around for instructions on YouTube on using Microsoft Paint. It took me longer than I expected because I erred in not being specific enough with my search parametres. The best search keywords I eventually used were "resize photo with Paint".
That got me some well focused instruction and I then successfully took one big photo out of the 12 Second Commute photo gallery and resized it down to half the original size. I like the following photo that I chose. I imagine some day I will be spending many of my days on a boat like the one in the picture, travelling the pleasantly scenic waterways of Canada and perhaps elsewhere.
I'm not sure that this is the best size for this format, though. Besides being able to resize using Paint, I can also resize using the 12SCBlog image posting tool. Look below, and you'll see the same image as above, but bigger. That is because when I posted it a second time, I changed the "layout width" and "height" numbers before clicking the "submit" button. It was 250x375. I changed it back to the original numbers, 500x750.
By the way, for both versions of the image, above, I selected "justifycenter" from the 12SCBlog toolbar to ensure that the pictures appear well centered in my blog.
There seems to me to be one main difference between MS Paint and the 12 Second Commute Blog Image Posting Tool, when it comes to adjusting the sizes of images. The 12SCBlog Image Posting Tool only allows the manipulation of image size through the use of pixel number input. MS Paint, on the other hand, allows both pixel number input as well as the far more user friendly option of revising the percentage of increase or decrease in size. What does that mean for you and me? Well, if you are not happy doing mathematical calculations to ensure that you maintain a proportional ratio between the height and width of your images as you seek to increase or decrease their size, then you really ought to stick to using third party image modification software, such as MS Paint. Me, however, I don't mind a little math. I actually like the challenge of making sure I've got the proportions right, so if I'm just going to be using an image and just want to resize it, I'll probably stick with the 12SCBlog Image Posting Tool, leaving Paint for more complex image manipulation tasks should I ever have a need for any of them.