Date: Different people put the date on different sides of the page. You can write this on the right or the left on the line after the address you are writing to. Write the month as a word.
Greetings:
1) Dear Sir or Madam or To whom it may concern:
If you do not know the name of the person you are writing to, use this.
2) Dear Mr Jenkins,
if you know the name, use the title (Mr, Mrs. Miss or Ms. Dr.etc.) and the surmame only. If you are writing to a woman and do not know if she uses Mrs or Miss, you can use Ms, which is for married and single women.