How to Insert an Image in WordPress

These instructions work for both posts and pages in WordPress.

Click the cursor at the start of the paragraph you want to put the image beside. Even if you are going to float the image to the right, you still click at the left, before the first word in the paragraph.
Click the little image to the right of Upload/Insert, above the editor. (If you hover your mouse over it, a tooltip will display “Add an Image”.) The screen will go grey and a popup window will display.
If you’re going to use a picture that has never been used in the blog before, click the Select Files button in the popup and then find the picture on your computer. Wait for it to upload – you will see a progress bar that says “Crunching” while it uploads. Then go to step 5.
If you want to insert a picture that has been used in the blog before, click Media Library. Find the image you want to use and click Show to the right of it. Then go to step 5.

Type in a description of what the picture is (e.g. “Photo of ABC Storefront”) in the Alternate Text box. This is for the search engines.
If you want a caption below it, fill in the Caption box.
Choose whether you want the picture Left, Center, or Right justified using the radio buttons. (I find that the design works more nicely when the image is to the right and not the left.)
WordPress automaticaly resizes the photo into several sizes for you, which are called Thumbnail, Medium, Large and Full Size. The dimensions of the images it has created are shown as ### x ###. The first number is the width and the second is the height; both are in pixels. Choose a good size. If you are floating text around an image, usually 300 pixels high or tall is good. For larger photos which are not going to have text beside them, and are usually centered, you can go to 450 pixels wide or tall.
Click Insert into Post (not Save all Changes; this just puts the image into the media library).
Now you will be back in the Add New Post or Edit Post page. Don’t forget to click the blue Publish/Update button in the post to save the picture in the post.