You will begin with the letterhead, which you will include the sender's company and their address. Secondly, put the date below the address and then get to the recipients address. After that, go to the salutation, which you will use "Dear Sir/ Madam" or "To whom it may concern". Next, go to the body paragraph and then close and put in your signature. Get a sample from http://www.writing.wisc.edu/Handbook/BusLetter_Block.html.