A lot of people have been asking me [Janna Guide]
So I thought I might as well make this public.
This is my personal pref. as of right now for playing Janna.
Runes: x6 Magic pen. (red) x3 Precision (red) x9 Armor (yellow) x9 Ability power (blue) x3 Ability power (Purple)
Masteries: I run a 12-18-0 using the keystone Windspeaker's Blessing But a 6-18-6 and a 0-18-12 both work well.
Abilities: R>W>Q>E
I start and max W due to the CD being now so high on her shield. Depending on the match-up, you can take E at level two, it doesn't have to be Q.
Why do I play like this? Well with Janna's constant nerfs to her E I find her much stronger as a hyper-aggressive support now. At level 1 and you start harassing the enemy ADC, they usually are caught off-guard. Your W scales both wonderfully with AP and also your movement speed. Not only that but it causes a massive slow which is life-threatening to them. The early game from what I find is rather hard to beat, and they will be forced to play under their turret or face a near-death to death scenario. When you have your Q, you are playing the same as before, press Q in the direction you want, let it charge, meanwhile you run up to them forcing them to go in the direction of your Q, use your W and proceed to AA them while the Q hits at max damage. At level 3, this combo alone will put most ADCs near 30% of their HP, all in a split second. I always rush Ardent and when I finally have it, you stop using your shield on yourself, and put it on your ally so your AAs are extremely strong.
I find this to be extremely useful at tilting the other team and giving them no time to think.
But yeah, just wanted to share this so hopefully I can stop typing it in /allchat.
Also, I don't recommend using this against an Ashe ADC for... reasons.