if you are replying to a message and want to insert pics there, just click "Upload a File" next to the "Post Reply" button and that will allow you to attach your own images. When you are making a new thread the button is the same, but is to the right of the "Create Thread" button. If you are inserting from a website you can click the button in the toolbar that looks like a cartoon mountain and sun inside a rectangle (to the right of the smiley face button) and then paste the URL.