As swim said there is a limited time when you can still edit your post. When you open the post you should see the buttons below: "quote" "reply" "edit" and "report." After a while the "edit" button is gone. So if you posted something and realized right away that you need to change it, use the edit feature. But once you can't edit it, just use the reply feature. You will be posting a reply to your own ad post. I see ladies do that a lot. Some do it just to add more pictures or information, others to correct something in the first post. I have seen that a lot with visiting ads, where the dates are incorrect in the first post, then corrected in the reply post. You can't post a new ad (start a new ad thread) within 7 days, but I don't think there are any restrictions on replies to your ad, because it stays in the same thread.

If for some reason, you don't want to do the reply thing (like there is some really blatant error in your ad, that you don't want anyone to see) and it is past the edit stage, then contact admin to remove it, or click on "report this post:" and have it deleted. Then you can post another after it is deleted.

I believe swim has answered your picture posting question.

the one page I read.