Not Updated For Current Season
Ok, first off, this is a JUNGLE nunu build. You can use this build for a laning Nunu as well, just change up the order of skills that you get. That is the only difference between my Jungle and Laning builds.
I start out with Doran's Ring for the mana regen and the ap off of it. I also grab a health potion just in case. Once i have 1200 gold, i recall to buy mercury's treads. Remember, Nunu is jungling, so everything can change depending on how well your team is doing. Jusst keep building up for the next item and you should be good to go for your item build.
Runes and Masteries:
These are by no means perfected yet, suggestions would be nice, but i will update them very soon and fix them to fit a tank Nunu.
Ok, reason i have to mention this, is just in case you have to lane as Nunu. I prefer to get Consume first still just to get some health back just in case. Since you are laning, you need to max Ice Blast and Blood Boil pretty fast and have consume last since it really won't help you against champions until it is maxed.
Ok, this is the long part. With this rune build and masteries, I have to start at the two golems first. I use Smite and Consume on one of them, and auto-attack the 2nd one until Consume comes off of cooldown. Then i run over to the wolves and eat the main one and auto-attack him once to kill him. The golems will get you to lvl 2 fairly quickly and I suggest getting ice blast in case you have to lane if someone dies or recalls.
After the wolves, run over to the blue golem buff. Eat one of the 2 minions gaurding him and then run over and kill the ghosts. This will get you lvl 3 and now you can easily kill the blue golem. Run over and Consume the golem and kill the minion with Iceblast and auto attacks. At this point, you can now kill anything in the jungle. At lvl 7, if you have Consume leveled up 3 times, you can possibly kill the dragon solo. You might need help, but you should be fine if you still have that health potion.
At lvl 4-5 you start being able to gank fairly well. Just ping on the map and call out who you are going for. Let them focus you and make sure to consume the minions so you get more hp back and are harder to kill. At lvl 6, you can start having some fun. Your ult is pretty op at the start and once you get an enemy champion stuck in it, you are almost gaurenteed a kill!
Now, remember to go back to base every now and then to buy items. Have the time i forget and i wind up with about 3k gold to spend. (oops) Be very careful if you were really annoying early game if you don't have Gaurdian Angel yet! I normally get my first death right before i buy it.
As the game progesses, you will notice that it takes you forever to die, especially with Flash and Consume. ALWAYS use Consume whenever possible! It restores your health and can keep you in fights for a long time.