You could take a flight from Dushanbe to Khorog. There is a 20 seater flight every morning to Khorog but its departure depends on weather conditions and the number of passengers. Tickets to the flight are sold a day in advance at the Dushanbe airport.
You could share/ hire a jeep from the jeep stand near the airport in Dushanbe to Khorog.
Same as getting in.
Rice, eggs, snacks, yak butter, bread, mutton, Pamiri tea (seer-chai), freshly made warm bread (non).
Tea, surprisingly good coffee, and vodka. Yak milk.
A zealous policeman in Murgab may want to register you with the police or complain if you were taking photos. This isn't a problem, registration should be known well enough simply getting to the area.
There is some risk of altitude sickness.