1 Whether you are issued a five or ten-year license depends on the mode of renewal.  It is advisable to renew your driver's license before the birthday on which it will expire. You can renew your driver's license within nine months of expiration date.
Price of a Stamp. The current price of a first class stamp is 49 cents. A domestic first class letter (1 oz.) is 49 cents. The price of each additional ounce is 21 cents. It will cost you 34 cents to send a domestic postcard.
According to the US Post Office postage calculator (link attached to this answer) the current cost for the most basic postage, first class letter to from the US to the UK, is 94 cents. If you don't want to go to the post office to get the exact postage you need, three first class stamps would do it. You'd be overpaying, though.