While typing your post you will see a "Go Advanced" button next to the "Post Quick Reply". Click that, then you will see your reply box for typing in, a box of smiley faces on the right, and a bunch of options below. One of those options is a "Manage Attachments" button. Click that. Then you will be able to browse your files to attach the right picture. Upload them and you will be good to go. Just continue to post your reply as you did before.
By the way: Sounds like you have a fun build getting going. I look forward to the pictures. And welcome to the greatest board on earth!
