As others have pointed out, photos can be added into a post by clicking the sun-mountain button labeled "Insert image URL". What may not be clear is that the picture(s) to be inserted must be posted on a photo sharing web site somewhere else. The free site that I have found to be the easiest one to use is Photobucket

You can create a free account using your real name or any handle you wish to use. You can organize your photos into "Albums". In my free account I have 9 albums and a total of 143 pictures uploaded and it is telling me that my storage is 1% full. So I still have a lot of room left. Uploading pictures to Photobucket is easy and intuitive.

To get the needed URL to place a picture into an AP post, do the following while you are signed into Photobucket:
1) Move your mouse pointer to the "Library" tab, then click "View Library".
2) If you have uploaded, or moved, your pictures into an album, then click on that album.
3) You will get a new screen showing all the pictures in that particular album. You can scroll up or down as needed
4) Move your mouse pointer onto the picture you want to include in your AP post. A button that sort of looks like a sun, or a gear, appears at the top right corner of the picture.
5) Move the mouse pointer onto this button and click on "Get Links..."
6) This lays another window with 4 options on top of the album page. Click on the "Direct Link" box which is the second one from the top. It briefly turns yellow and the word "Copied" appears.
7) Click the "X" to close this box.
8) Back to your AP post page, make sure that your cursor in where you want to insert the picture and then click the "Sun Mountain" button labeled "Insert image URL" at the top of the AP text box. This button is the 4th one from the right, just above the AP text box.
9) You get a pop-up box that says "Please, enter the URL for the image that you want to add.". The "http:\\" in this box has a black background with white letters. You can ignore this as it will be overlayed in the next step.
10) Point your mouse into this box and right-click, then click on "Paste". The Photobucket URL will appear in the box.
12) Optional check - Hit your "Home" key. This moves your view to the left side of the box. Look to make sure you that have only one "http:\\" there If you have two it will not work.
13) Click "OK" and the pop-up box will close and go away.
14) Click the "Preview" tab at the bottom of the AP text page. You should see your picture incorporated into your text.

This sounds a lot more complicated than it really is. Once you have done it a few times it is easy and straightforward. I have tried to include ALL the steps, but step 14 "Preview" is the most important. You can make changes by scrolling below the Preview section. It doesn't go anywhere until you click "Post message".

This method also works well with other blogs, like RailroadForums, so you only have to upload pictures ONCE and can post them on many different sites if you wish to do so.

Photobucket has a lot more good options which I have not yet checked out. I appreciate the fact that they don't plague you with a bunch of ads and don't bug you to "upgrade".

If you want to see an example of a AP post with an imbedded Photobucket picture in it, click this link: AP post with imbedded Photobucket images

Good luck, and we look forward to seeing some of your pictures posted.