Subject on ar_mailer

Does anybody here knows how to include an e-mail subject using ar_mailer?
When the model is created, there is no subject field.
Other question: do I have to create a new method (like send_newsletter) on the Mailer that inherits from ActioMailer::ARMailer?
Thanks in advance.
Att.

Rodrigo Felix de Almeida
Promine Tecnologia da Informação
Gerente de Projetos
Sun Certified Java Programmer