Hello everyone!
Welcome to my Rammus guide!

First of all everybody should think that rammus is totally useless for support and we had to use it for jungle. I tried rammus as support so many times and i had to say that he can be a very good tanky/support, and extremly troll champion.

Standard tank runes nothing to say about this.
Flat armor seals, leveling magic resist glyphs, hp quintessence, and magic pen marks for the better dps.

Early game you should build yourself as a support, yes in the recommended items i didn't mentioned the wards,but i think it is base thing for support if you play this role you know you have to buy wards and where to put it. I usually start with a Pendant because much easier to stay on lane. Philosopher's stone for the mana regen and the gold/10sec, heart of gold hp+gold what else needed? After the Mercury treads i start to build my self as a tank. i think that much more easier to support somebody if you tank the enemy. While you're tanking the ad carry can do his/her job: dmg the enemy.

Pros.

-With tanky itembuild and good escape abilities nearly impossible to kill.
-Ultimate trolling champion
-Your passive makes you a rampaging beast on late game.
-Awesome dance
-Turtle

Cons

-Easy to accidentaly steal kill on early game
-If you play this champion like other support you're completely useless
-With tenacity easy to counter

Team work! Don't be a hero. You're a tank, you cannot kill everybody actually this is not even your job. Your job is to tank, stun, taunt and scare the sh*t out of the enemy.
You shouldn't have to play Rammus like other normal support. You should be very agressive and help the ad carry to get fed. Taunt the enemy then stun with powerball, then use defensive ball curl to get enough resists to tank the damage. In teamfights same, target somebody do the same combo then pop your ulti and smile. Don't fear to tank in mid and late game, you're an overpowered turtle.

I use powerball for stunning only. Taunt and defensive ball curl is the most important. Your ultimate is useable only for teamfight no use in 1v1. Max your defensive ball first then taunt and the ulti of course.

Flash.
Cv.
Nothing else needed, flash for greater escape or to taunt somebody. CV because of the support role, use it for reveal enemys in the brush.