There have been several threads about this recently...
I've done this as a MR twice in the past 9 months. On LAX-SYD, they serve dinner immediately after take-off (last time was a choice between a chicken and a pasta), a snack exactly half-way through (at about the seven hour mark, last time was a cold sandwich), and then breakfast about an hour before landing (for breakfast, think hot breakfast sandwich).
The good FAs bring water around throughout the flight.
Both times I did the trip, there were power ports in the first 10 rows of the coach cabin, which I took advantage of.
Enjoy!