how do you write an etiquette introduction to a business letter?

Question

A business letter from a law firm who is sending it out to let people know about their firm.

Answer 1

Do you mean eloquent?

Or are you asking what is the etiquette, because there is none, just sell your skills.
What's your specialty, years in the business, cases won, settlement figures, whatever might move people to hire you first.
Edit yourself down to two short paragraphs and it might get read.
You will also need a professional logo.
Nice stationary is an unnecessary expense (I work for the US Attorney's office) nobody cares about that, it's the quality of your service that people remember.

Answer 2

To whom it my concern;
This letter is to inform the public of a new Law office that has recently opened in your area named "Laywer Name". (list a brief history and specialties of all who work there.
blah, blah, blah
Thank you for your time and consideration in all your future laywer needs.
Very truly yours;
John Doe

Answer 3

start with a brief history of the firm,then the partners and their speciality with contact information.

Answer 4

I agree, you start with Dear Sir John and end up with yours sincerely as you have a name. It would be yours faithfully if you did not have a name.