Not Updated For Current Season
This is most likely similar to other guides.
I made this one mainly for myself because this is how I like to build my Janna.
Way to play:
-Don't be to bad at the game.
-Lane with someone who is good early game.
PS. I know Heal and Clarity together are bad. If you don't want heal and Clarity then chose Clairvoyance, Flash, Exhaust instead. It's completely up to you. I suggest using Clarity though, it's great for team fights and is also great to stay in your lane.