Could someone instruct me on how to upload a banner? That's all I really need, thanks!
Sure! I know a ton about technology and I've helped a few people here already.
What a lot of people do is they upload a banner to a picture site. Photobucket, Imageshack and Imgur are some I've used.
Generally, you will need to create an account in order to upload. All of the above are or have a free component to their site.
If you need help with this, every site is a bit different, so go through any tours or instructions you can when you get started on any site.
You'll then need a "IMG code" for your picture from your picture site in order to continue.
Go into the profile link at the top of almost any page of the forum, and select Forum Profile Information.
Find the Signature section and paste in the IMG code. Format it however you wish.
Click the "Change Profile" button and the changes will take immediate effect.
Then, just go to any of your posts and you should see your new signature in effect.