Edit : I finally got around to updating this to reflect the newer forum software. If anything is wrong or needs more clarification, let me know.
First, click on "My Controls" at the top of any forum page.
Nexxt, click "Your Albums"
If you haven't previously created any albums you get this screen. Enter a name for your album and choose to make it public. Then click "Create Album"
After the album is created, in the drop down window, select "Upload Image"
First, browse to the image on your computer that you want to upload.
Second, name the file. You cannot upload the file uless you name it something.
Third, click "Post Image"
After the image is uploaded, you will see a new page showing your image.
With Firefox, right click on the image and select "Copy Image Location".
In IE, right click on the image and select "Properties", then highlight and copy the "address".
Then navigate to your post, click the "Insert Image" icon, right click on "HTTP://" and paste in the copied image location.
You end up with something that looks like this.
I usaully choose to "Preview Post" nexxt to make sure everything went as planned before I post it.
You're good to go!