First you need to click in the "edit area" below the toolbar at the place you want to add the image

Then click on the Image icon (looks like mountains) in the toolbar a dialog box will pop up

Link to an image already in the internet

Alternative Text is displayed if the image does not show, also it helps accessibility for people who cannot see the image

You can also link your image to another web page or image with the Link tab (you can leave the Target as <not set>)

hint, if you link the image, then set the border to 0 !

Result:

keep in mind that unless you own the account or web site, the image may be removed at some point

so it's safest to upload the image - see next steps

Upload an image from your computer

Click on the Upload tab and Browse to the image file you want to upload, then click on Send it to the Server

You will get a confirmation that the image was uploaded then you will see the main image dialog tab to adjust the size, border

Once you are finished editing the image properties, click on OK and the image will be inserted.

Don't forget to Save your work to publish it.

Result:

Editing and deleting your images

After you insert an image you can always edit it by clicking on the image then in the Image icon,

or you can delete it by clicking on it and pressing the delete key