Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
I love Flash and Ghost with this character. Even if you follow the exact build that I have given to you, you have a lot of health but you're still kind of squishy given that you don't have much armor and ganks are very common. These two spells make for a quick getaway in almost all instances so you can live to keep on fighting. You could use Ignite or Clarity as well I suppose, but I love the ones I've chosen for this build.
I like to space out my masteries with Brand. I feel like if you max out one of them early, you leave the others under powered. When you have them all at decent levels and working in tandem, Brand's combo (Conflagration-Sear-Pillar of Flame-Pyroclasm) is extra devastating. Your Conflagration sets them aflame, and the Sear stuns them long enough to put your Pillar of Flame and Pyroclasm to good use. If you can get some champions grouped together, Pyroclasm REALLY puts the hurt on 'em when it bounces. With a good amount of AP, you can get that ult to do 550-600 dmg or better on every bounce.
I always buy the same 7 items first every time I play Brand, regardless of the other team. Catalyst gives you a good health/mana boost early game, and rushing the Rod of Ages after that gives you some decent AP and health over the course of the early game. I usually build Rylai's Crystal Scepter after the Rod to give me a serious amount of health for damage soaking ability. However, if you have a couple of tanks on your team or you need a boost of damage, don't hesitate to build Rabadon's Deathcap next. That'll give you an awesome AP boost for pwnage, and you can worry about building Rylai's after the Deathcap. I think both Rylai's and the Deathcap are indispensable to my build, but you can sub one in for the other as the need arises. Grab a Zhonya's Hourglass after that, even if only for the AP and the activated ability that puts you into stasis. The armor on it is an added bonus against any melee you encounter. Lastly, the Void Staff is icing on the cake. It gives you extra magic pen over and above what the boots give you, plus the 70 AP added to your already awesome amount. With this build, you'll be melting faces in no time!