You need to upload the photos to the page as a file attachment. It's another section on the Edit page.
Where do I find the url-of-photo? It is the one given in the File Attachments section of the Blog Entry you uploaded it to. If the photo is for your Intro then the best Blog Entry to upload it to would be your first one (the oldest). Scroll to the bottom of the page below the message box and click on File Attachment.
Click on Browse and locate the picture file on your computer and click on it. Click Open in the box the picture will be uploaded to your blog entry.



