Don't know if it counts as an 'official' answer, but..
A format I have used in the past is as follows:
Salutation (Sir,)
Para 1 - BRIEF personal history intro;
Para 2 - What you are looking forward to in your new position and what experience you bring to it; and
Para 3 - Extra-curricular acitivities (not baking or cross-stitch, but rather things that would be pertinent to your new job and any extra duties it may entail i.e. adventure training, team sports, etc).
Closing statement (Sincerely,)
If you want to be really archaic, use the formal British Army closing statement;
I remain,
Sir,
Your obediant servant,