The 3 points you want to get across can be accomplished in just a couple of sentences that include (a) your announcement that you are quitting, (b) as of a certain date, and (c) provide information about your last day.
The Thank You. Next, it's always a good idea to thank your employer for the opportunity, describing some of the key things you've enjoyed and learned on the job. And yes, this is true even if you're thrilled to be leaving. Remember__you may need these people for a reference down the line, and leaving things on a good note will leave a lasting (positive) impression.