You will need to write your address (unless you have a professional letterhead which already covers this data), along with the address of the business or person you are writing to.
Your address should be written first, at the top left corner of the page in the following order:
The address of the person to whom you are writing should then be written below your address in the following order:
Organization (if relevant)
If you do not know the name and gender of the person to whom you are writing, then you may simply write: Dear Sir/Madam, but if you do know the name or gender of the person to whom you are writing it is more appropriate to refer to them as specifically as possible. I.e, if you know their names, then write them out in full.
If the person you are writing to is a woman that you know to be married, then you may address her as Mrs. But if you don't know for sure, or would simply like to be on the safer side, you may use the title "Ms", which is applicable to both married and unmarried women.
Note that you may or may not choose to include a subject line before just before or right after your salutations. If you do choose to include one, it should look something like this: "Subject: Employment Letter Format".
The body of a formal letter in block format will not have the indentation at the beginning of paragraphs which is the norm in more conventional letter writing.
Instead, every line should start at the same point and be on the same level.
If you are familiar with the person to whom your letter is addressed, you may close the letter with " Yours Sincerely", but if you’re not then you should close with "Yours Faithfully".
Most word processors come with an inbuilt "block" option and you may usually utilize this by highlighting your text and then clicking on the block icon.