Here's how you embed pictures into your post. This is assuming your picture hosting place allows hotlinking.
Step 1 - Bring up the picture you want to attach. Right click on the image and you'll see "Address/URL" in the pop up window. Highlight that URL and copy it.
Step 2 - Click on the "Image" icon on the Reply toolbar. That will open a small box. PASTE the URL that you just copied from Step 1 into this box. Click Ok. That's it.
If you want to practice, you're more than welcome to use the Lateral-g Skid Pad to try it out.
Hope this helps/makes sense.