We have just returned from an amazing fortnight in Orebic. Everything was fantastic and we had no complaints.
The address and postcode on the homeaway site plugged into the sat nav took us direct to the door, however there is a VERY sharp right turn onto the access road, so i would advise passing the access road and heading on in the direction of orebic until you find somewhere to pull in and turn.
The villa is family owned, and Antonia was there to meet us as we had sent text message to give arrival time. Antonia and her Dad were so friendly, and Antonia always available to help us with a few queries.
The supermarket "maxi Konzum" is 5 mins along the road in the direction of Orebic.
We spent a lot of time just at the villa drinking in the fantastic views and enjoying the pool, but Orebic town easy 5-10 mins in car. There is a huge cheap carpark in Orebic down on the front, and loads of places to eat and drink.
From Orebic you can also get the car ferry, or the passenger ferry, to Korcula. If you plan to visit the old town (and you should) rather than driving around the island, you should leave the car in Orebic, and get the smaller passenger only ferry which takes you to the old town itself. It's cheap and the timetables are available online.
We also got a taxi in to Orebic using the local cab service "Taxi Tabo". It was 80 Kuna, which seemed a bit steep, but it's handy to have the option.
Closer to the villa; there are 2 restaurants / bars within the campsites at the shore directly below the villa. They were good value, with friendly staff, and we enjoyed a dip in the sea whilst waiting for our food. Walking down takes 5 mins - when you get to the main road - cross direcly over and head straight down the hill towards the "winery Mikulic" and then you will find the restaurants.
We also visited Mali Ston (good place to stop off as halfway from airport to villa), and Trstenik which is a beautiful sleepy seaside resort 25 mins from the villa.
Overall we had an amazing time, and can't wait to return.