How do I put my signature at the bottom of new message

I am new to MACs and OSX - when I reply to an e-mail, my signature remains at the bottom of the e-mail, under the originator’s e-mail address rather than at the end of my message. I dont see any existing rule that will allow me to change this - do I need to create a script?

Also - anyone know how to send a contact as an e-card attached to an e-mail?

Thanks very much!!! javascript:emoticon(‘:D’)