Moved to Help & Support / Errors & Bug Reports I'm assuming that you are talking about the signature below your post. To do this you need to go up to where is says your username on the top right of the forums. Scroll over it and a drop down menu will appear, then select signature. From there you can upload a picture and edit your signature.
adding to what da_tirtow said, i recommend placing the banner on your desktop, then heading over to imgur. Get the image uploaded on imgur, and then click on the image after it loads. It should bring you to a .png file. Copy that and go back to the forums. Click the picture of the tree and paste the .png into there. It should work as Ive done this many times *looks below*
This was moved to the help/support section for a reason. Also, threads are not locked in this section.
Well obliviusly he doesn't, so what if he is a mayor, is he not allowed help. Instead of saying that why don't you help him??
It's a quote, you click the button at the bottom right of the person's post that says "Reply" It's under the forum rating icons.