Well this is my first guide i will try to make it better and better so please don't complain and if you like it i will be thankful if you vote it up so it can be good for other people too.

Why did i choose the runes?
*Ap runes are really good they will give extra health to the consume spell
*The reason why i choose the attack speed runes is to use the passive more often and give as many blues as possible to the mid
*The armor is as simple as you lose less health in the jungle

I choose to start of with regrowt pendant and hp pot because you don't really lose that much health and the health you lose will the regrowth pendant give back. Then the Philosopher's Stone it's an easy choice because it gives mana regen and hp regen that will be very useful and then the gold per 10 will help alot.

The reason i choose the rod of ages was because i like being a bit tanky and it gives me a lot
more mana and it also gives some ap. Then the sheen is useful to hit between each ice blast and then when you get the lich bane it will be even more useful. You can choose the swiftness instead of magic penetration as i do because it will be easier to hit them when they have been slowed. You can already guess why i choose rabadon's deathcap it is for the single purpose dmg. Then frozen heart is not always the right item if you meet an team that is heavy ap and don't have ad carry this is not a good choice then i would choose an abyssal scepter for the magic resist or maybe an banshee's veil.

Now in the beggining you want to go to the blue and let someone leach it or how it's spelled and you are going to attack it and wait for it to take down about 100 health from you then you use your consume and finishing it with smite. Then you go to the wolves and consume the biggest one and kill the other two with ice balls and basics. Nunu is really good at counter jungling and stealing buffs because of his consume that deals more true damadge than a smite sometimes. When you are stealing buffs make sure you have a flash on Nunu so you can escape, you will should lure them into the bush next to the buffs so it's only you that can see it.

For you that don't know it i will tell the basics of nunu.

He's passive will give him a free spell every time he has used basic attack 5 times. When you know that you can either choose mana regen or you can choose lower mana regen and choose attack speed for more dmg. The reason why i pick attack speed is to give little more dmg and be able to trigger the passive more often (this will trigger wriggle's lantern more often too).

Now when we know that we can use the passive and ice blast to harass chapions when we def towers without wasting mana. When we choose champions it's important to attack the ad carry with ice blast and use your blood boil on your ad carry. Ice blast slows their attack speed with 25%. And that gives them less dmg. The blood boil will increase movment and attack speed to you and the champion that you select (Shpuld be the ad carry/solo top) this will increase the champions attack speed and give him/her more dmg. If the ad carry is too far away pick someone closer and throw iceballs to poke down their health remember that when you do this your slow gives you and oppertunity to run away (be careful for stuns).