Copy the text or URL of an image or website. Click the Quote, Image or URL button. This will place a start marker. Paste in the text or URL to the image or website. Click the button again. This will place a stop marker (same marker but with a "/") at the end of the text or URL.

Or, you can paste in the text or URL, select it and push the button once. This will place the appropriate marker at the beginning and end of the text or URL.

Selecting text and pushing the "B", "i", or "u" button will also do bold, italic, or underline.

I hope that helps.