Solid build, pretty effective too. Keep it up

nice guide man, i will try some tips ;)

Pretty good build from a newcomer. I'll have to give it a try next time Amumu rolls on the free list.

Check out my Jarvan guide in return?

I have to write a comment so... HI :D

Thanks for your input dude, your comment helps for sure. I'll try to explain more or less all those points, and change some things as well.

-Most of the times I have not enough gold to buy a Giant Bell on my first trip back so at the end I buy HoG first, I'll change that. Only reason to delay it was getting Sunfire asap as it helps a lot with farm, jungle camps and it hurts enemies nicely early on.

-Items I put in the list above are my main choices, core is HoG+Sunfire+Negatron, from there on all are situational, this means any combination of them or even other items I didn't list but I mentioned is ok.

-It's still possible to kill mushrooms as a melee though it's hard not to proc'em if they're in a bush. Anyway you can always reveal them so your ranged mates kick'em.

-I'll try out going Warmog against balanced teams, it makes sense that you can tank both AP and AD damagers but this is situational. I prefer having some strong resistances first, as well as some HP, and maybe then Health is the most viable stat. But I don't think you can tank a whole team just with a lot of health, any Kogmaw-Warwick-Shaco with Madred (Brand with his passive) shuts you down fast.

About laning masteries and buff duration.. I find it still useful for Baron or random buffs you get when you kill someone with them, I'm not a fan of Greed or Perseverance. Early Oracle was thought in case nobody else got it and you know enemy team is warding all over the map, but supports should take it over you IMO. Rylai is that great I agree, it's a good item on Amu but if I get it I usually do as my 6th item, I feel I need other stats before I can afford it. It's a luxury item but synergizes good. Lastly Frozen Heart pick, it's a good item for sure but I feel Randuin's Omen is good against ANY team with at least 1 AD damager, while Frozen Hearth loses it's effectiveness against a balanced team. Remember Randuin's active also slows, not only debuffs attack speed. I'd consinder FH a situational item.

Thanks so much for your comment again ;D

For gold items, you may want to get them earlier if possible (You get them quite late for jungler build). Heart of Gold also gives quite a decent amount of hp, for less than Giant's Belt.

As for items, I don't usually see much games that you get far enough to 8 end game items (or maybe you may have written wrongly).

Mushrooms cannot be killed by most melee champions, seeing that you have a short range and spells don't affect it.

Health items are the best when teams are balanced - You can tank ADs and AP damagers

Your laning build shouldn't add utility buff much. Its usually better for carries to take them instead, which means it won't be that useful on you.

Unless there are invis champions/lots of wards, oracle isn't as useful as saving up money for the 3 pots combo (if you don't get much gold late game)

Rylai is really useful seeing it does a big AOE slow around you that costs very little. Its like a perma slow when you get close up and personal.

Personally, I prefer Frozen Heart as compared to Randuin's Omen. Frozen heart gives mp, 99 armor and 20% cdr. On most Amumus, after a fail bandage toss/long ulti cd, your team might get rushed and easily destroyed seeing your team saving abilities are gone for the moment. Frozen Heart also has Randuin's Omen attack speed slow effect, but no movement speed slow (usually Rylai makes up for this), no regen (usually regen is not exactly that useful late game) and no gold item (So the cost is roughly the same, so long as you don't buy Randuin in one shot, but Warden's Mail is better than HoG, so you may have a lot of problems deciding)

Other than that, its a good guide :)
Hope it helps :)