Alright, this is my first guide. I made it for Brand cause I've been playing him a lot lately and I'm really enjoying how he plays (Almost as much as Trynd :3) Anyways, not a guide that's well tested, seeing as I'm not even lvl 30 :*( . But hopefully this will still be a good build. :D
This build is intended as a guide for beginners or people who want to try something a bit new. I don't think anyone has a build exactly like this. Sorry if I'm copying anyone but the only Brand build I've read is the one by Duk3Star.

I would like to start by explaining the use of Clarity as a summoner spell for Brand. Brand can be very mana starved in the early stages of the game. Taking Clarity as a summoner spell has seemed to fix this issue when I have played. It allows Brand to stay in lane and keep pushing/harassing, while still having enough mana to protect himself in case of a fight. The second summoner spell, however, is really up to the player. I prefer teleport because it gets me to where I need to be faster than anything else. If you require an escape mechanic then you probably made a bad choice. Play safely and you will get to farm creeps and champs. :D

So given that Brand has clarity as a summoner spell, we can assume he doesn't require as much mana, or mana regen, from runes. This allows us to take AP seals or really any seals. The magic pen marks keep tanks from shutting down your damage completely early game. And the CD reduction Glyphs help Brand recharge his slightly long abilities. For Quints, really you can take magic pen, CD reduction, or health. Magic pen for more damage, CD reduction to be ready whenever you need to be, or health for early game survivability. If you find you overextend early game often you should take HP quints.

This mastery build focuses on damage and mana. The extra 9% CD reduction from Sorcery and Intelligence really helps throughout the whole game. Archaic knowledge in my opinion is a must, extra spell pen for free! It's a great mastery. Also, the points in Deadliness and Good Hands, as well as Awareness, can be switched out for any masteries that give a bonus to your summoner ability. This is just an average mastery build.

Alright, now we can talk about item choice.
Archangels Staff: Early Game I find rushing an Archangels Staff can really allow me to harass much better. The extra mana and mana regen that you get from building the staff is great. If you're playing right and you still have your first tower up by the time you finish this item, you're well on your way to pwning face late game. The most important thing to do though is to FARM THE PASSIVE. That extra 1k mana and bonus 30AP can allow you to just spam abilities for massive damage late game, and not even put a dent in your mana pool.

Sorcerer's Shoes: These provide the extra spell pen you need to get through that tanks Force of Nature. You should be finishing boots right after you finish your Archangels.

Rabadon's Deathcap: Great item to rush. Big damage boost mid game. They never see it coming. This item is an AP stacker's best friend. If you find you're in a game where you cannot stack AP though this item may not be worth your time. For instance if you are getting nuked down before you can even move, go for a Moonflare Spellblade if they're using cc's, or a Hextech Revolver and eventually a Will of the Ancients if you're team is AP heavy or you just want spell vamp.

Void Staff: Bread and Butter, bringing those tanks down on their knees, and completely decimating everyone else's magic resist. If you're against alot of melee that like to target you, or a lot of casters that like to target you, get an Abysal Scepter.

Morello's Evil Tome: A great item, Mp5, AP, and CDR all in one. Only possible tradeout on this one would be Deathfire Grasp for tank killin'.

Lastly you can really do whatever. I like Zhonya's Hourglass because it keeps me from dying in critical situations while still providing a fair amount of AP.

If you don't play Brand you might want to know how to combo.
It's really really really easy. Just don't miss you're skill shot :D.
Stun/Damage Combo: Conflagarate-> Sear-> Pillar Of Fire
AOE Max Dmg: Sear-> Conflag.-> Pillar
Team Fight Multiple Target: Add ult to above
Team Fight Single Target: Add ult to top combo :D
Make sure you make the right decisions on where and when to use abilities during team fights. It could be the difference between a win or a loss. ( or a triple kill :3 )

Get your Pillar first! It is the most useful harass/farm Brand has. This will allow you to hit creeps and champs, sometimes both at once. Maxing this out ASAP will give you the long range harass you need to stay out of tower range, and the ability to farm like a pro :). Used with conflagarate you can farm creeps all day long. Sear is mostly used for it's stun and application of Brand's passive. It is not as useful to max until late game. Also a good thing to keep in mind is that if you cannot hit your skill shot or your pillar start getting ranks in conflagarate. It can also be used as a good range harass.

Hope you enjoyed the build, sorry I are teh n00bs (No pictures :( cause I am noob.) I would really appreciate feedback, thanks bai!