This is my first build and I don't really want to make it all fancy. I would just like to get everyone to have as much fun with him, as I do. And sense it's my first build, feed back is much appreciated :)

Greater Mark of Magic Penetration
Greater Seal of Regeneration
Greater Glyph of Magic Penetration
Greater Quintessence of Magic Penetration

I know it seems like I have too much magic penetration, but I was using the runes that I bought for a different champion, and they seem to work quite well. Rammus's attacks are magic based and the extra magic penetration works well. I have been using cooldown runes lately and they seem to work very well as well.

Rammus is the most flexible champ in my opinion to buy items for. You basically have to buy what you need for that game. This is the most basic sequence that I buy but according to who my opponent is and how they are doing is what determines the order of which I buy my items. If there is a Yi, Xin, or Panth, etc. I hurry armor first. If there is a huge amount of casters I rush Force of Nature or Guardian Angel With Rammus, if I don't get my resistances up fast enough then I work on my Defense Ball to help keep me protected.

If I am playing a DPS heavy team, Ninja Tabs are nice boots because they are cheap and give me just enough armor and dodge for the beginning. But if I am going against a CC heavy team or a magic heavy team, I prefer to buy Mercury Threads.

Depending on whether who is my lane and who my partner is, has a huge part of my skill sequence. If i'm solo and turret hugging, my taunt is always my priority. If I have 2 casters then my defensive ball is a priority.

I have tried many summoner spells with Rammus but for a typical game, exhaust and ignite seem to work well. Ball, Defensive Ball Curl, Taunt, Ult seems to do the trick almost always but exhaust works wonders against an OP melee or a fleeing opponent. Rammus does alot of damage even with as tanky as he is. But ignite seems to do it faster :)

Rammus is nasty champion and with a decent team, should almost always win. I have seen many jungle with him and rape but I prefer just to lane. Try him and out and try my build out. Please let me know what I did right and what I did wrong. I am new to this :p