Hey Big Bob,
To insert an image, or a few, when you reply to the thread, just under the text box field, click the 'Attachments and other options' link. The link will expand and you then click on 'Browse'. At that point, locate the picture you want to upload from the folder where you have saved it and then add the attachment. If you need to add multiple pictures, then select 'more attachments' as many times as you need to depending on the number of pictures you want to add. As you select the pictures, you will see the file name within each field.
Once you are done, and you have typed anything you want to include in the textbox, then you select post which will upload your reply with the pictures attached. You can also preview before you post. Hope this helps and we are looking forward to those pictures.