Log in to your SkyMiles account by visiting the Delta website and clicking on the SkyMiles link. Entering your name and password signs you in to your account where you can begin booking tickets.
Click on the link to "Book Award Trip". The number of SkyMiles needed to book a trip differs from flight to flight; you need multiple SkyMiles to book an award ticket.
Enter the details of your award flight. Choose whether or not your flight is one way, roundtrip or multi-city. Enter your departure information, arrival information and the number of tickets you want to book.
View the list of available flights and select the one that best suits your travel needs. Click on that flight to continue booking your award ticket. Enter the passenger information, which includes the passenger's name and birth date. Because you are already logged in to your SkyMiles account your personal information is already saved, which means you do not have to re-enter it.
Confirm your flight details and click "Book Award Ticket". Delta subtracts the number of SkyMiles needed to book your flight from your SkyMiles account.