The '08 model year is different in that is it doesn't have the two levels of service.
Every year - at least.
Every 6,000 miles; so if you do 24,000 miles in a year thats four service visits.
Page 163 of the handbook is your oracle.
If you had your bike serviced at 3,000 miles (for whatever reason i.e. has it been a year since the last service?) then the next service is due at 9,000 miles or 12 months hence.
The date and mileage of the next service should be entered in the service book.
A service reminder display comes on before you reach the required mileage.