Rammus is (in my opinion) one of the best tanks in the game, he is a giant meat shield, that can deal almost as much as he can take. Every team dread seeing a Rammus on the other team and your team will love you for it :). I usually play rammus laning but he is a very good jungler aswell and have experimenting with jungling and didn't really enjoy it to be honest but i,ve put in a guide for it aswell for all you junglers out there :).

Pro's
-Best tank in game
-great damage output
-can take a heap of damage
-good escape
-can tank towers
-can jungle

Cons
- Most people rely on you]
- your not invincible :(

Early game you should be focusing on last hitting minions whenever you can and abusing the enemy at your tower with taunt only do this if they are harassing you into the ground and have gotten a bit cocky, and have forgotten you even as a threat, then put em in their place and let the turret do the work and you might even grab a quick kill. Although it is great if you're pushing their tower instead.

Mid game you will be either in a team fight, pushing a lane, ganking or just trying to get some good farm in or even trying to get red or blue buff, i like to let someone more suitable to grab the red and blue buff.

Late Game is when the proper team fights have begun during this time you will be pushing or defending mid or another lane, if you know you can take the other team and be a good tank and initiate the fight then communicate with your team so they know what's going on, and you might just win the team fight, and pushing your way to their inhibitor or even the win.

Initiate with a Powerball, Puncturing Taunt the nearest carry, Defensive Ball Curl it to soak up the damage and Soaring Slam to deal some damage, remember to not let them near your squishies there is nothing worth all of your carries dying and not being able to do any damage, if you can taunt them to stop doing damage to your carries and hope your carries survive.

Items:

Core

Mercury's Treads - You will usually get this item every game it gives a fair bit of magic resist and reduces debuffs by quite a bit, you could pick up a Ninja Tabi if their entire team is physical then sure pick it up, it gives some armour and a chance to dodge which is always good :)

Aegis of the Legion - This is a great item, most people pass it by due to its poor stats but its aura that makes it great it will give you and your allies some armour and magic resist and giving yourself health aswell.

Thornmail - Has perfect synergy with your thornmail and your Defensive Ball Curl, the more people hit you the more they punish themselves :). Apart from its great passive it has the most armour in the game and is a item made for rammus.

Banshee's Veil - Apart from giving you extra health, mana and magic resist, this item will block one spell from you can make you much harder to kill when they're first spell doesn't do its job properly.

Sunfire Aegis - Another great item this item gives you extra health and armour, also its passive is bloody good aswell. Now when people hit you at close range they will be getting 30% of that hit against them but you will also be doing 40 magic damage a second to them aswell, combined with your ult this is a great combo.

Guardian Angel - By this point in the game you will have sold your doran shield and will get this bad boy, the stats are very good giving you a lot of armour and magic resist aswell as giving you the power to come back to life :o. This item will make it almost impossible to kill you, you should be a giant meatshield making the other team do hardly any damage to you unless they have a Last Whisper or Void Staff, nonetheless you should be bloody hard to kill.

Jungling:
haven't really jungled much with Rammus never really thought of him that way, but it works. Jungling the first skill you'd want to get is get a Defensive Ball Curl and your first item of choice should be a pretty standard Cloth Armor 5 health pots, this will allow you to take blue buff quickly and still be in the jungle for longer. Remember to take smite though like any good jungler would. Also this is the route I take.

The route I take:

1- Blue Buff first - remember to pop that health pot the second the big guy hits you

2- The wolf camp

3- Wraith camp

4- Red Buff

5- The big golem guys - remember to have your smite ready though

Repeat or recall.

By the time your level 4 you can even go off ganking if you feel the need, if a lane needs some help then go help them, better to lose jungling time then a tower. Although i usually like to gank around level 6.

Marks - To be honest Im not sure what to get with rammus as i usually build him pure tank so i decided to with a standard Greater Mark of Desolation.

Seal - For Seals i decided to grab Greater Seal of Armor for more armour and a advantage earlier in-game and its good for jungling too.

Glyphs - For Glyphs i got Greater Glyph of Magic Resist just to get me more magic resist.

Quints - For Quints i got the Greater Quintessence of Armor but i suppose getting Greater Quintessence of Health is still a viable choice.

What I use

Flash - I pretty much get this for every champion because i find it a good way to get away and a good way to catch up to an enemy, remember to use it through walls it can give you heaps of ground that your chaser needs to pick up and most likely you'll get away.

Exhaust - A preferable preference, good for catching enemies who are running and can greatly reduce the other team's carry effectiveness. But these are just the abilities that i use you can grab what you want but this is just what i use :).

Viable

Ghost - You can get this but it is more of an escaping ability and you,ve already got your powerball for that :L. but this plus powerball will make you go super fast.

Ignite - if your looking for that early first blood then i suppose you could get this but i usually let the carry get this because in the end they will need the kill more.

Teleport - if you like getting back into the fight and being able to level up then go for it its just not my thing though.

Heal - If you want to get first blood its good for bating enemies into it when your low on health and then you suddenly have half health, and you get the kill :).

Cleanse - Good for getting out of stuns or slows but i always forget to use it xD.

Do not Get

Clairvoyance - let the support get this.

Clarity - Can be good early game but it is really **** later game and wont really help you much.

Fortify - no. not for our brick ****house

Revive - no.