You can upload your pictures to the Gallery:
http://www.parrotchatter.com/gallery/index.php
The Gallery will automatically resize your picture for posting.

After uploading, click on the picture. Copy the script.
This is what you will be pasting into the 'Script Box'
on your 'Reply to Thread' screen.



On your "Reply to Thread" screen
Click on the Yellow box with the Mountain (Insert Image)



A box will come up where you will paste the picture script.
Paste, then click OK



The picture will be inserted into your post.