Do you mean posting dragons in your signature? You just go to your forum profile -> modify profile -> forum profile and you will see a box where you can add a signature. Above the box and the emoticons you will see an egg icon with dc written on it. If you press it, you will see this: [ dc ][ /dc ].
Now you just add the code of one of your dragons in the middle like this but without spaces [ dc ] 33qSH [ /dc ] and you will see this in your signature when you save your profile:
You can do this multiple times with the code of other eggs/hatchlings and simply change them once they grow up.
If you want a little info box with your scroll stats linking to your scroll, you can make one here for example (scroll down to signature generator: http://eatw.net/tool.html
Once generated, you just add the link you get to your signature (see above)
It will look like this: