Full name and address details.
Date
Reference if required.
Dear (Mr/Mrs/Ms Surname)
(optional heading, bold or underlined - normally the job title and or reference if they've asked you to quote one)
I enclose my CV in respect of the above vacancy/position (or state position advertised and when it appeared). You will see that I have the required skills, capabilities and experience for this position, notably (state two or three attributes briefly).
I look forward to hearing from you.
Yours sincerely
(Sign)
(And below print your name - not hand-written)