Janna was my first buy and I have always enjoyed her play style, I believe it is totally under-appreciated by most people. This is a guide to playing Janna as a support, hence the title. It is certainly not one of those silly AP Janna guides. Think selflessly while playing her and you will do wonders for your team.

Clairvoyance is a certain must have for any support in my opinion. There may be a support/tank or somebody else like Nocturn who can use it effectively, and then it is up to you and your team to decide what to do.

Flash is a great for obvious reasons. You shouldn't really be initiating with it unless you can pull off a flash>Ult on a person, pushing them into your team while separating the others if there are any.

Ghost is OK but Janna is pretty fast already and if you play correctly it isn't necessary to use as a getaway.

Teleport I went through a phase where I thought this was a good choice, but I was wrong. Just follow your carry around and babysit that puppy...

Exhaust is OK if nobody else has it on your team.

Choosing what to buy as a support is all about who you are laning with/against.

Doran's Ring is my choice when I am going to be in a lane with somebody who is either not a good harasser or does not use mana.

Mana Manipulator is for those times when i am laning with somebody who uses mana and can use their abilities to harass well.

Boots Health Potion sight ward This is a smart choice if you think that there will be an early gank in your lane and you might be overextending.

Don't do it (unless you are for some strange reason solo laning = should have picked a different champion).
The only excuse you have to farm is if your partner is horrrrible at last hitting or is a lost hope.

ionian boots