To upload photos - First of all you need to ensure the photos are hosted somewhere such as Flickr. www.flickr.com (Free site) and that you have selected for anyone to see them.
Once this is done you can start to post pictures. Personally I use Firefox but I assume it will be similar for Explorer.
You will need to get the address location of your picture so (using Flickr) click on the photo you want to upload. Once this is done you will need to click on the 'Share This' link on the top right of the page. Then in the box that opens up click on the 'Grab HTML'. Then copy the image location that appears starting from 'http' and ending 'jpg' in the drop down box.
When you post there should be a tool bar available under the message header. Located on this is an icon of a picture of a tree. Click on this and it will bring up a little box. The top line will say Image URL. Paste the URL you previously copied here. Then set the Image Alignment. Once this is done the dimensions of your image should be shown. You may need to resize the image if it is too large (more than 400 pixels) as this really peeves of the Mods! Then just click on 'Insert' and job done!!