New comer!!!

Hi,
This is my first day on this forum and I hope to learn a lot, especially how to write any kind of letter, the approriate words to be used at the beginning and at end of a letter, the format of of letter and ...just everything. By the way my first language is French, and I heard the format of the letters are differents in English. The first thing I'd therefore like to know is the locations of the address field(s).