I think your mistake is that you are clicking on "NEW TOPIC" at the top of the page. (A topic is the same thing as a thread, not a post.) Instead, you should click on "reply" on any post in the
Post Your Music & Gear Place Picture ! thread.
To get your image to display, you first need your image address. Click on your image link to open your image. Then copy the address. Go back to edit your post. Paste the link in between {img} and {/img}.
But use the square brackets [ ] instead of the curved { } ones! You've just made "BBCode."
For example: {img}
http://forums.rolandclan.info/pub/attach/174230-KRE8A_Picture.jpg{/img}
With the correct brackets, this becomes:
Since you've already uploaded your image, you don't have to upload it again; it's already on the server. You can just copy and paste the above BBCode and change the brackets.