This advice applies to Top Mid ADC and is advisable against most matchups. I cannot advise you pick Quinn into a few no-no matchups: Talon Diana Malzahar. Akali and Katarina are fine because the former is weak long enough for you to impact other lanes and the latter's ult can be interrupted by your Vault. Pick Quinn if you want to play an aggressive lane and snowball other lanes off of your strong early-mid game. Think of Quinn's roaming as Twisted Fate's perhaps that helps?

While I posted Exhaust as the secondary summoner, you can take ignite teleport or barrier as you see fit depending on the lane matchup. In general, Exhaust is best against burst damage, Teleport is for the times that Quinn just doesn't move fast enough for you, Barrier is ideal against d.o.t. like Malzahar or Rumble, and Ignite is for when you are very confident you will kill your lane opponent. Additionally, you can take Ghost or Heal for an extra speedy engage/disengage.

With the change to make her Q lack a blind but apply her passive, Quinn's early burst is pretty decent. if a stack of your passive is on an opponent, they will either be zoned in fear of said burst or hit by your aa-q-aa-e-aa combo. With a point in your W
Since her Q now has its cooldown halved if it kills a unit and works as an execute, don't be afraid to use it to last hit.

At 6, Quinn suddenly has a 70% movement speed boost to roam with. Before you do this, you should back and pick up Zeal. This is so you have crit chance to reduce the cooldown on your passive. If you can get boots they will make your falcon speed that much faster. Thus the recommended backing gold would be ~1600, or the Season 5 BF back. If your lane isn't immediately in danger, you should try to impact another one! Ult on fountain to conserve mana and fly to whichever lane is pushed up, when the target is in range of your E use it to engage, this will activate the effect of skystrike while keeping you close in the case that they flash while not putting you under tower. From here, use the aa-q-aa combo to get off as many procs of your passive as possible! Your burst with the support of whoever you're ganking for should lead to a nice kill. You then ult to return to your lane in a timely manner.

Once you have Static Shiv and the red Static Shiv, your purchase order should hinge on who's big. I recommend Triforce for decent sustained damage, or Deadman's Plate for burst. Both items give some tank stats will also emphasizing extra damage. The reason Deadman's is so great on Quinn in this build is it will work with Shiv and red Shiv's procs for super-potent initial aa burst, while giving ridiculous speed when flying about.