This is my 2nd guide on Mobafire. 8D This time about Alistar, my favorite support. This guide is about how to succsesfully both support at early game and tank at end. I'll be talking about what Items I prefer and viable items on him. So enjoy reading my walls of text. ^^

I'm trying to get as much Hp I can early game with Hp mark and Hp Quints, this gives me enough Hp to play agressive in lane so me and my AD carry can dominate. I take the Mana-reg Seals for more heals so your Carry gets better sustain so he/she can farm longer and thats just what you want as a support.
And last I take my Magic-resistance plvl Glyphs cause I find that you really need that magic resistance for endgame, but if you want to you can take flat magic res or CDR/CDR plvl, its all about what you want.

I go with the regular 0/9/21 with my Alistar cause I want that extra Hp and Armor with the 9 points in Defense. You could take Hp Reg here instead but I prefer the Hp plvl ones.
I put 21 points in Utility for obvious reasons. The extra CDR on Flash, more movement speed, more GP10 more Exp, CDR and Summoner CDR, what more can you wish for a support? :D

This is probably my favorite build on Alistar. It makes you really tanky, and that movement you have with Boots of Mobility is GREAT for Alistar!
The Shurelya's Reverie for CDR, Hp and the AoE Movementspeed buff is really great when Initating fights and such. ^^ Force of Nature cause of the massive Magic Resistance AND Even more Movement speed. xD Yes I love Movement for Alistar, I hope you get that about now. Frozen Heart for CDR, Mana and Armor + the 20% Attack Speed Reduction for your Opponents will make characters like Tryndamere almost useless, and thats why I have my Randuins Omen to. And Banshees for obvious reasons.

I think that Alistar doesnt need Mercery Tread's cause he got his pretty imba ult. Ninja Tabi could be Viable on him but I dont really know. I think this is one of best ways to build Alistar, you got High defense, high Maric Resist, high Hp, so your gonna be ALOT tanky and still have your support role. Which really really great.
And this is a 6-build guide, but if you dont need all 6 items buy wards on the last slot.

Early game just try to play agressive, W + Q them when the get to close to minions or if you got enough time Q + W to knock them to your AD carry. Heal whenever your Ad carry is missing Hp and you got Mana. Dont waste to much Mana in the early laning phase cause you'll need it when your jungler ganks and such.

End game when you got your Randuins and Shurelya's your activation combo should look something like this.
Pop Shurelya's + W + Q Pop Randuin and if you get hit by a stun/fear/tank etc. Just pop Ult and they have 1 CC less which can be the difference from winning a teamfight and losing. And then heal whenever your team gets hit but your probably just gonna heal 2-3 a fight but its some atleast. :d
With this spell sequence your a really good initator, but it would be best if you had an Ashe or something in your team that has a long-rang initating ultimate. Alistar is porbably the best and hardest support in the game, if you miss your W + Q combo you'll just knock them back if they dont stand against a thick wall, so when learning this I recommand you to NOT have smart-cast on cause thats makes it ALOT harder. Just try to learn how to use that combo and you'll be able to dominate in game.

Summoner spells, regular support. What more do I have to say. Cv and Flash.

Something really important for a support/tank is that your the teams initator, you should have the Oracle, you should ward and you should assist your team as much as possible in any way possible. Alistar should just try to focus his CC in teamfights on the AP or AD carry so the rest of your team can just burst them down easy, well thats prob all teamwork you've to know. :d

This is one of the most efficiant ways of playing Alistar. His probably one of the only heroes who can play Support and Tank on the same time so if you learn how to use him you can carry a full team in Elo Hell with him, hes that Imba if used right. My avarage score is about 0/5/20 in Ranked and I got most wins with Alistar. So now go in Ranked right away and try this out. :3