If you're trying to use her Q on champions for damage, charge it from a bush and just try to lead it as best as you can.
During the laning phase, use it for farming/pushing against minions and initiation against your lane opponents. If you hit the gank phase with her, your best bet is to usually queue it up from whatever bush you're going to come from in anticipation of the enemy running from you. Makes it really easy to then set-up your ult to throw them into your allies and slow them when they try to run back past you (don't break the ult until they run back to it). In team fights, you just want to knock up as many enemies as you can in one shot, or keep someone from running (though her W can do that just fine, too).
If you're laned solo, 2v1, or with another support or a tank or something, rank your Q as first. If you're laned with a solid DPS, rank your E to keep them alive and give a huge damage boost early game. Generally, one rank W is all you'll need for most of the game (which is sad because it's my favorite of her abilities).
Most commonly you'll see her built straight AP (RoA, a Ring, Soulstealer, etc.), though an aura/support build isn't that rare (Soul Shroud, Will of the Ancients, Aegis). Occasionally you'll even see AD/AS Janna, which is actually pretty fun to play. Grab a LW and an IE and lawl as people try to escape your awesomeness.
EDIT: Typed all of that without actually mentioning the thing that made me hit "reply" in the first place: the biggest reason to charge her Q, really, is to boost the movement speed. The extra damage is always nice, of course, but damage isn't what Janna's about.
During the laning phase, use it for farming/pushing against minions and initiation against your lane opponents. If you hit the gank phase with her, your best bet is to usually queue it up from whatever bush you're going to come from in anticipation of the enemy running from you. Makes it really easy to then set-up your ult to throw them into your allies and slow them when they try to run back past you (don't break the ult until they run back to it). In team fights, you just want to knock up as many enemies as you can in one shot, or keep someone from running (though her W can do that just fine, too).
If you're laned solo, 2v1, or with another support or a tank or something, rank your Q as first. If you're laned with a solid DPS, rank your E to keep them alive and give a huge damage boost early game. Generally, one rank W is all you'll need for most of the game (which is sad because it's my favorite of her abilities).
Most commonly you'll see her built straight AP (RoA, a Ring, Soulstealer, etc.), though an aura/support build isn't that rare (Soul Shroud, Will of the Ancients, Aegis). Occasionally you'll even see AD/AS Janna, which is actually pretty fun to play. Grab a LW and an IE and lawl as people try to escape your awesomeness.
EDIT: Typed all of that without actually mentioning the thing that made me hit "reply" in the first place: the biggest reason to charge her Q, really, is to boost the movement speed. The extra damage is always nice, of course, but damage isn't what Janna's about.
![[Image: Kaden2.jpg]](http://img.photobucket.com/albums/v403/Nezumi16/Sigs/Kaden2.jpg)
"It's on my brain, driving me insane. It's on my mind, all of
the time, and if it left... I would be fine."

