Grabbed this from Reddit. Basically details all the popular supports:
Now for the support breakdown, to better understand what supports do better against the other lanes.
Alistar - He has such a strong kit that it has fallen victim to nerfs many times. I rarely play Alistar anymore because he is different from most supports. He requires a melee range position so it's a whole different ballgame. This was fine when he had the full glory of his ult, but after his last ult nerf I find myself getting blown up like I don't even have an ult, it has discouraged me from picking him many times. Season 1 I had a 57% win-rate with him but season 2 I am only 40% with him becuase of his nerfs(the flash nerf hurt him a lot too). Now, Alistar does well with lanes that push, why? Because most of the time alistar is useless in the middle of the lane unless you "wombo combo" which is pulling off your WQ abilities at the same time, which is great for harass... but doesn't often secure a kill. Alistar's happyzone is either pushed onto your turret or pushed onto theirs, for example if you are working with a trist, and you are pushing the lane, you want to be at the end of the bush cloest to their turret and when they come in to CS you want to step out and W them against the wall briefly stunning them giving yoru AD time to follow up, after that brief stun is done with you want to Q them into the air, try to space out your abilities as much as possible while keeping them in the same spot to get maximum damage from your passive. Also, I try to start the game with a pink ward because warding a bush against alistar destroys most of his pressure. having a pink to contorl the bush is how you will win your lane. Keep in mind your W has a range of 650, so you can hit any carry that is going in for a cs by comboing them. Don't do it too often as it will burn through your mana fast. I tend to avoid picking Alistar against a kog'maw or vayne because of how easily they can go through your ult. Be careful against sivir as well, her shielding one of those abilities gives her a huge advantage.
Janna - by far my favorite. I believe Janna to be the strongest support but the people at my elo just don't understand how to utilize her in lane. Many times when I have picked Janna in draft people will ask me to change to something with sustain because they don't feel Janna is going to help them win. Janna relies on mitigation, knowing when an AD is going to go in for harass is the most important thing to know when laning with Janna, shielding as much damage as you can. You don't trade when you have a janna, think of it as having a blitz, you sit there and wait for an oportunity then you go all in to either get a kill or knock them out of lane. Most of the time if you want to sit there and have a harass war with an AD, whoever has the Janna will fall behind due to the lack of heals. Always try and kite the enemy with Janna, she is very fast for a reason. moving to get into a position to throw a tornado that will line up with both enemies in the lane is something that is very important to her strength. I tend to pick her a lot to counter aoe teams (kennen fiddle morg) and when I have a late game AD carry. Her passive is also to be taken into account, If I have other people on my team that rely on mobility such as garen/udyr/gp/nid ect ect. Janna is a great pick, that 3% passive helps throughout the whole game.
Soraka - I'm not sure I should even explain anything about her, I never played her in season 1 because of how boring and easy she is. If someone has a channeled ability save your silence. If someone has ignite on them and the person attacking them is already peeled WAIT to heal them until ignite is gone (sad how often I see that.) Heal your carry that is being his by their AD, not by the caster derp. no sense in wasting half of the strength of your heal. Stay behind everyone, since you have no escape and no peel as long as you are in the correct position no one will go for you unless they are dumb (sad how often I see this as well). Just know that ADs know to go on offense when your armor buff wears off so whenever it's on cooldown be on alert. Almost forgot. 90% of the time the enemy picks Alistar support I pick soraka to counter it, as I said above Alistar's W range is 650. Soraka's E range is 725 so if he is going in to do some punishing Soraka can stop it long enough for your carry to reposition himself. Not many people realize how hard Soraka counters Alistar because of this.
Sona - I don't often play sona for the same reason as soraka, I find her a bit boring but she is still very strong. THe thing I love about sona so much is how adapable she is. It's not often I level up her abilities in the same way twice. My skill order depends on how my lane is going, if we are doing well? q first, if we are losing the lane I'll level W for the resistance (or if enemy karth). Some games you don't even have to get your E until level 12. As far as playing her she does well from the bush. Now, her auto attack range is 550 and her Q range is 700, so anytime you get in range for a Q idealy you want to throw 1 auto attack as well, sona is so strong early if the enemy team doesn't ward the bush to stop you it's going to hurt them. Auto attacking from a bush reveals you to be harassed back so you want to learn to quickly step out of a bush, get your auto attack off, then step back in before they can return the favor.
Taric - Probably the best bush zoner as his mid lane zoning is stronger than Alistars, Know that his stunr ange is 625 so he does well against any carry but cait/ashe and kog depending on his W obviously. Taric works well with anyone who is strong early and is great at securing kills while offering good mitigation with his armor aura. Works best with ezreal and cait from what I have seen. ezreal can get in position and put a lot of damage down while their armor is shredded. Cait gets the job done because she can almost always follow up on the stun because of her range. Taric does not have good mana so make sure that if you are going to use the stun your carry can follow up on it. One dumb thing I see a lot of silly tarics do is shatter before using their ult, always use the ult first so you have the AP buff that makes shatter hit harder. There are two ways I generally start taric's items. Boots and 1/2 wards or faerie charm with a pink and a few wards. If the enemy team wards your bush it hurts taric's viability a lot, Taric is the strongest at the beginning of the game, take advantage of it so you don't fall off so hard late game. Be careful when picking taric that you aren't gimping your late game. Just like I explained with Alistar do the same with taric, when the enemy AD goes in to CS drop the stun on them as they are going in, they will be close enough to your AD to follow up. If you have a comp like Garen Ezreal Taric, don't expect to win after 30 minutes. As I said above about soraka countering Alistar Taric does it in a different way. If alistar is coming in to wombo combo you, ready your stun on him and as he gets in range for his W it will go off and he will be stunned before he can get his Q off to stop you, so it will actually save you. It's very satisfying. Also, because Taric's stun is rather slow sivir tends to shield it most of the time, try to avoid doing that matchup.
This wasn't exactly meant to show you everything about to support. I'm not talking about runes/masteries, when and where to ward, item builds. I just want people to better understand picks and how to help your carries do their job, they need you more than you know, support isn't just "oh I get the easy job of getting to sit back" that's how you throw games dumbass.