-I'm not going to type a bunch of non sense for you to read. Here's the build. This is meant as a CARRY build. It can serve as a support build, but it is meant for Orianna's looking to go mid, get FB, and destroy the **** out of the enemy team.

-First, lets go over what kind of champ Orianna is. She has one of the longest ranges in the game, but is squishy at the start of the game, and also extremely, extremely slow. I cannot stress enough how slow she is. But you're in luck. Command: Dissonance is a skill that not only deals damage, it will also boost Orianna's (and any allies') speed if they walk through the area of effect, and slow any enemy champs if they walk through the area of effect. Orianna also has a shield (Command: Protection) that will come in very handy to help shield you from minor damage, and even give you that extra 50 health you need to stay alive as you dash to a turret.

-For the build, I like to start with Doran's Ring. Its a good go-to item for casters, and it gives you AP as well as mana regen, both very important to Orianna. After getting Doran's Ring, try to stack at least 1 health pot when you return to base the next time. These will keep you in lane much longer. I usually stack 2 when I go back to get Tear of the Goddess. Definitely gives you an edge in the middle lane.

-Skill order when casting is simple. Harass constantly with Command: Attack. If you hit the enemy champ, always pop Command: Dissonance for extra damage and a slow. You can also throw out with Attack and then retract with Command: Protect for quick harassment. In a team fight, or when just going for a kill, throw out the ball and try to get somewhat on or behind the enemy champ(s). Pop Command: Shockwave, stunning the target, immediately followed by Dissonance. If you have it timed right, you can be running towards the target this whole time and being to auto attack, which adds bonus damage up to 3 stacks. If you feel the need, ignite them and Voila! You have yourself a kill. Using shockwave is also good for getting out of sticky situations. If you find yourself about to be ganked, throw the ball onto the enemy champ(s) and cast shock wave. Whip the ball back to you with protection, and then cast dissonance for a speed boost to you, and a slow to the enemy champ(s).

-Runes should be self explanatory. The reason I go with 3 0.65% CD Glyph's is because you want that FB right out of the gate. Orianna is very reliant on having low CD's for her abilities. The more times you can swing your orb around, the more damage you can do, and the more your Tear Of the Goddess will stack mana for you, and the more weary the enemy champ will be.

-ALWAYS be middle lane. Even if you're not that great with Orianna, you're the best harass in the game. You should be able to get every minion kill since you have two forms of attack, and if you keep you orb behind enemy minions, it should provide enough of a scare for the enemy champ to keep a bit of distance.
-A good tip for laning: constantly keep your orb behind enemy minions. It allows you to hit the enemy champion(s) for more damage, since you're avoiding the minion hits negating your orbs damage.

-BE WARY OF GANKS. Orianna is one of the SLOWEST characters in the game at the start. This build requires you to get boots at about 7-10 minutes, so don't over extend. It will cost you more than just one feed. Dying causes you to lose all position you had, and the enemy champ will not have any problem harassing you back, now that he's seen how squishy you really are.

-Also, be ready to gank! Orianna may not be fast, but if you can find a situation in which enemy top or bottom has over extended themselves, get there and throw the orb out! Slow them down first with Dissonance, and then pull them back in with shock wave, allowing your teammates to assist you in getting the kill.

-Orianna should be going for blue every chance she gets. I usually wait until level 6-7 to go at it, but after that point you should have it each and every time it spawns.

-Your Protection skill works great for teammates as well! Cast it on a tank at the beginning/middle of a team fight for an extra edge, or throw it on a low HP teammate trying to escape. My favorite trick is to toss it on a teammate who is low and running from enemies, hit him with protect and pop dissonance immediately. He gets away, and the enemies get slowed/mad.
I usually follow this quick combo with "Lol u mad bro."

-The end of the build is meant as an option. Personally, I go GA, but Banshee's has served me well too. Even going with something for more dps like Void Staff can be beneficial. It all depends on the situation you are in at end game. If you're completely pushing the enemy nexus, go more AP. If its pretty even or you guys are losing, go with something to help boost your HP and keep you alive longer.

-The key to Orianna is getting her health early on! The more health, the longer she can lane, the more damage she can do! Good luck, I hope this build serves you as well as it has me!

Here's what I've been able to do so far with this build: