To begin with you have to ask yourself, "Does my story have news worthy potential?" If it does, then read on....

First of all try to gather the most important facts about your story. You don't have to write it out like a piece in the paper, but you do have to gain the interest of the journalist reading so salient facts and a human angle are most important.

Begin your release with the release date, If you are promoting an event that will happen next month and you would like to promote it about a week before the actual event, put that date at the top. For example if your event happens on the 26th of the month write: For Release on the 19th of XX 200X.
However if your story is happening right away put: "For Immediate Release" instead.

This ensures that your story will be printed at the relevant time.

Next comes the Who, What, Why, Where and When. Answer these questions in order. Dedicate about a paragraph to each.

Think about whether your event would be a good photographic opportunity and if so add a request for a photographer, the journalist will decide whether to send one. (This will cost you nothing unless you decide to purchase prints of the photographs afterwards)

(I don't recommend taking photographs yourself unless there isn't a professional photographer available. The pro knows how get the best quality for the paper.)

Make sure you include all of the relevant facts and if you have verbatim quotes from any relevant people add those as well.

If you have trouble adding the quotes or facts into the right sections then add them after as bullet points.

Once you have finished your piece add two blank lines and then add "ENDS" to make sure that the journalist knows you have finished what you are saying.

After "ENDS" add another two blank spaces and put:

Contact Name: (your name/any special title goes here )
Contact Number: (your contact number goes here)
Contact Time: (A good time to contact you goes here)

You can also add any other contact information if you need to, the more you add the better the journalist can get hold of you if they need to.

Good Luck and happy writing!