Glenn, first you write your post. Then you scroll down a little, and look for 'manage attachments". From there, you can browse to your photo (I put mine in a folder on the desktop) and upload it. Then remember to click "submit" to post the whole thing.
For uploading your photos, here is a good thread:
http://forum.bonsaitalk.com/133309-post26.html
You need to resize them so that they are small enough. Here is a good link for that:
http://www.shrinkpictures.com/
Joanie