Well, it looks as if I have no choice but to do a Rammus Guide.
First off, a little about Rammus. He is a tanky, trash talking, mutant, armadillo from the desert. His character doesn't emote for shit, and the only interactions you get from him are grunts and the occasional, guttural, "Okay." Despite this, he still manages to taunt his oppenents into attacking him (a feat I shall never understand). Rammus, at first glance, is your run of the mill tank. His passive scales his damage based on how much armor he has(a tragic downfall for many Rammus. I will explain later). But is there more than meets the eye?
Powerball- Easily one of best moves to utilize for movement in the game. While Rammus may not rip through jungle creeps as fast as some junglers, and while he doesn't simply regen all of his life from attacking, his movement through the jungle is unparralled. In fact, with a good leash, one can finish through you own jungle in under 4 minutes with both buffs and be rolling to gank a lane much faster than other characters. This move maintains its usefulness late game by acting as a mechanism to initiate teamfights, as well as knock characters out of certain ults because of the knockback effect on powerball interrupts some (not all) channels. Got a Warwick on your ass ready to ult? Roll out and laugh when he gets knocked out of his ult the instant he uses it on you because of powerball.
Defense Ball Curl- A turret divers best friend. It massively increases your armor (and your damage by proxy) and your MR, making you far harder to harass as well. This move doesn't really have any hidden usefullness, but it takes some time to learn to time right. Oh, and if you want to be a dick, just DFC when Teemo is about to attack you and watch his movement speed go to shit. He will think twice about it from then on. One thing to be careful about DFC is that if you are attacked with it up while on an enemy turret, THE TURRET WILL ATTACK YOU! It is considering attacking an enemy, so while it will take out that damn rat teemo, it will also destroy use. Be careful when DFCing to increase damage output(by passive) on an turret.
Taunt- THIS move is what Rammus is known for. Grabbing people with taunt, running them past your turret, into your base, and onto the Nexus. I exaggerate, of course, but losing control of your character for 2,3,4 seconds? And the faster you are, the more debilitating this move is. I have had games where I drag a bear stance Udyr LITERALLY from his 3rd tier tower almost to his 2nd tier. Needless to say, he died. Not only does the individual lose control, but they lose armor while taunted. If you have a physical carry, they will love you
Tremors - Rammus' ult can go one way or the other as far as usefullness. If you suck at timing it, it is completely useless, as most characters will just run out of range and blast your face. Basically, it just creates an AOE effect with Rammus in the center that damages nearby opponents AND structures. This is a two edged sword. While you can rape towers with your ult, if you hit a player while trying to destroy a tower and get caught you are screwed. Protip, towers hurt.
Gameplay - Essentially the only way I ever play Rammus now is in the jungle. Lane Rammus is about as weak as Lane Amumu IMO and only if you are playing casually shoudl you play him in lane. Besides his weakness in lane, his ganking potential is GODLIKE! Okay, you can move faster in spurts that any other character (powerball) you can taunt and not only disable an enemy champion, but have them hurts themselves on your DFC while you are running them in the opposite direction from where they want to go. Gank a lane with a stunner on your team? Someone is dying. On top of this, if you are level 6 and have your ult, you can push with your two teamates and crush the tower even faster. One good gank and you can easily have a double kill into a turret. This is why Rammus is feared.
Skill Order for jungle rammus is DFC first, then powerball, then taunt at level 3. From there on, skill level up goes Tremors > Taunt > DFC > Powerball.
Jungle Order on Rammus is start at blue (no mana regen basically rapes your movement speed and capacity to kill) to wolf camp, to wraiths, to red, to golems.
Starting items are cloth armor and the rest of your gold worth of red pots.
When you start at blue golem, if at all possible get a leash, but DO NOT pop your DBC and start attcking. Instead, just normal attack until the golem turns around on you. THEN pop your DBC and a potion. Otherwise, you waste the extra damage that is returned to golem by your DBC and you take extra damage. Once he gets down low enough, smite him and immediately get powerball. You should need to use another pot at this point and roll into the CENTER of the wolf camp. Then use DBC and spread out the hits evenly among the wolves. This makes it so they are all low when your DBC is down and you can powerball them all down at the same time. Then pop another pot and walk to wraiths, where you powerball into the center of them, yet again. Focus the big wraith, and let you DBC kill the little ones. Then, pop another pot, and go for the red buff, hitting the center again and DBCing. At this point you should see the pattern. Smite should be up perfectly in time to kill lizard, (kill the little lizards first if they have one hit left if you are low on health. Two DBCs will put them at one hit normally.) Then go rape golems, making sure to hit both. At this point, if your health is low, you can roll in, DBC and focus one golem. When DBC is down, walk away and kite the golem until it is up. You are now level 4 with both sets of buffs and enough gold to buy a HOG or some boots.
From here.... wait for part 2 where we talk about the PvP ganking aspect.
Note here that you can gank at any point past level 2 or 3, but only when overextension is really obvious on certain chars. Like a karthus without flash. That just screams kill me.