A couple things finally helped me (thanks to Janice).
1. If you have an iphone, use it to take pictures.
2. Log in to QB, go to the Pictures forum (or whichever forum you want to post your pic), hit "post new thread" and wait for the text screen to appear. Then click on the little "insert image' icon. The screen will prompt you to Choose File. You want to click that, then find the photo in your photo stream and click on it. Then hit 'Upload file." It should appear on your post. You may then write anything you want along with the picture.
Option 2: Email the photo to yourself. Before it sends, it'll ask you to choose size "small", "medium", or "large" ; click medium or small to be sure you're not going to have size problems. I think the file can't be bigger than 200KB? I'm no guru by a long shot. I just have found that two methods work.