just to say i am in silver 2

Okay. First of all, if you want to learn the game, there are better ways than writing a guide. Writing guides are for people who already know of the way to play the champion or a specific method of playing a champion (even if it's for a troll build, etc). You are better off starting a thread in the forums and asking people for help.

Having said that, it's nice that you wrote a guide, since it will show a lot of what you are doing right and/or wrong, but there really isn't much here other than a build setup.

Let's begin.

1) Don't splash your runes so much in different stats. This is not a 'style' thing, so don't use that excuse. You don't get a lot of stats from runes to begin with, so focusing them is practically a must. At a stretch, you should splash two different types of stats in the same type of runes, so running 3 different types of Marks is considered very sub-optimal.

2) Learn to skill appropriately. A basic of Leagues is that you should max abilities by level 9, 13 and 18, with points in ultimate at 6, 11 and 16 (there are some exceptions). On Amumu, I believe you max Tantrum (E) by level 9 first. Maxing abilities usually come with stronger benefits than maxing indiscriminately - sometimes the cooldowns are reduced on a major ability, or the base damage are big.

3) Learn to use mastery points appropriately. The reason 21 points are taking in any tree is ALWAYS for the point at the very bottom. In the defense mastery, Tenacious is AMAZING for tanks to prevent them from being held down by crowd controls (stuns, snares, slows, etc). If you are taking 21 points, you MUST take the bottom point. Allocate your points appropriately to achieve this.

4) Similarly, when 9 points are taken, there is an important point there as well. In utility, this is Runic Affinity , which is VERY useful on junglers, since they take a lot of the buffs.

5) You need to learn what items are actually good. From what I can see, you just chose a random assortment of items and just threw them together. You need a rationale behind what you are building and why.

http://www.probuilds.net/champions/Amumu

Aside from the Summoner Spells, you got just about everything wrong. Just because it appears to 'work' in your games doesn't mean it's a good setup. It may appear like it works just because you've won one game in ranked, but in actuality, I know for a fact that you haven't tried the runes yourself, because you don't even have a full rune-set at the moment. You are still very new to the game and it will benefit you more if you learn the basics (which you clearly don't know yet) before you go into ranked.

i know this is very badly detailed but its my first guide so any constructive criticism would help but this works for me so i guess it isnt that bad. And yes i know the runes are weird but like i said it fits my style of jungle :).