How do I put pictures into my Yedda answers?

It's very simple-

You should first be able to link directly to the image, which means that the file should be online in order to add to your answer. You can upload it to Image Shack, or any other image sharing service that you use. You should then copy the URL given by the service you used, click on "Add Image", on the top of the answer text box, and simply paste the URL into the pop up window. 

You can actually just copy the picture and paste it into the answer box and it will automatically upload into your answer.

For your easy facilitation of your question you can ask Yedda people how to do it. They would gladly answer you back.