To add an image to a post:
1) Directly from your computer. Click on the "Upload attachment" tab just below the "Save Preview Submit" buttons in your new post window. Click the "Browse" button and navigate to the picture you want to upload. You can add a comment to the picture at this time also. Double click on the picture then click the "Add the file" button.
You can add several pictures by repeating this process. When you are done click the "Submit" button.
2) You can link to an outside picture posting website like Photobucket or Picassa once your picture is there. The way to get the link to the picture is different for each picture posting website. Here is an example of that:

You click on the "Img" button above the post text box and insert your link between the two image statements ( img and /img enclosed in square brackets [] )
NOTE: the filesize of attachments must be less than 2 Mb or you get an "invalid file" error.
Unfortunately most cameras now take huge pictures (file size is huge) so to upload a picture here you will have to take a lower quality picture or use one of several available methods to resize the picture before uploading.
Also, if the file size is too small you will get a "The upload was rejected because the uploaded file was identified as a possible attack vector." error.

I am experimenting to see where that threshold is. So far it looks like the minimum file size needs to be about 150 Kb.
I changed some BB settings so that the uploaded pictures display as a thumbnail 800 pixels wide. You can click on the picture to see the full size image.
I also changed a setting so that the uploaded pictures display in the order you uploaded them.
