Scroll down the page when you are replying or posting and look for the additional options. There you will see the upload photo button. Click on that button and then left click on the "Browse" button and then browse though your hard drive to find the post. Then click the "upload" button. The picture should upload from your hard drive to the post. It will show as a link to the picture until you complete and click the post button for your post. Go back and check your post to see the photo. Note: only certain file endings are allowed for photos in here.
Note: When I say "Click" I'm meaning to Left Click the Mouse button on the icon or button.
Congratulations on the catch. A 15" long crappie is a great catch.