This is a build for Annie. If you are interested in playing Annie, it is for one reason: You want to destroy people. Either that or you have an extreme attraction to fire or little girls. If you follow this build and play intelligently, you will destroy people. Provided, your team isn't a bunch of non-English speakers or ******s. In this build, I will cover just about everything you need to know about Annie.

Pros:
-Early game farming is a breeze
-Best spike nuker in the game
-Can turn a 2v3 into a 3v3
-You can send a kamikaze in to turret-dive/check bushes
-People don't expect your raw power
-She skips when she runs
-Tibbers is cute

Cons:
-Squishy until you get Catalyst/Rod of Ages
-Slight mana issues in the beginning of mid game if you aren't conservative
-Somewhat team dependent

The runes and masteries that I have listed above are just what I recommend, but not necessary. Annie is fairly variable when it comes to this. Some prefer to get health quints for a little more survivability but I don't bother, that only gives plus 78 health. Sure, it's useful for early game survivability, but if you're smart then you won't need it. I'd much rather have the ability power quints.

Lots of people like to use the Greed mastery from the utility tree. My question is...why? It generates 1 gold every 10 seconds. That's only 180 gold generated in a half hour which is only the equivalent of like 6 minions kills...I'll pass. I'd much rather have a point in Blink of an Eye to reduce the cooldown of Flash. It doesn't really matter if you put the fourth utility point in Haste or Good Hands. Both are decent, but I'd rather have the Haste for better chance of escape from a gank or for chasing somebody down.

When it comes to summoner spells, I prefer to use Flash and Ghost. Flash is a must because it is useful for escaping, for popping out of a bush for a surprise gank, or for just getting ahead for the finishing Q as the hopeless idiot attempts to run away. Her second summoner spell is variable:
-Ghost: is what I recommend just because it is useful to escape or to chase somebody down (or more than one person)
-Ignite: is commonly used but I don't see it being that useful except for stopping that annoying ultimate from Mundo
-Teleport: is acceptable for getting back to the lane from shopping/death/or saving a turret
-Clairvoyance: leave this to the support
-Exhaust: Meh...it's okay I guess
-Clarity: You shouldn't need it
-Heal: Alright but you shouldn't need it
-Revive: You shouldn't be dying alot if you're smart
-Cleanse: Just flash...it's better
-Fortify: Leave it to the tank
-Rally: lol.
-Smite: Jungling Annie ftw?

Annie has a few items that are variable. My build sequence above is just my preference.

I can't imagine starting Annie with anything other than a Doran's Ring. It gives plus 100 health for a bit more survivability, plus 10 ability power which isn't much but you can't complain with having a bit of a head start to awesomeness, and most importantly, it gives that amazing mana regen. As long as you are not reckless with your mana, you will never have a problem with the Doran's Ring.

Many people do not like Mejai's Soulstealer because they just don't like snowballing items. This just means one thing: these people suck with Annie. A real Annie player will get a Soulstealer because they know that they have the intelligence to survive and preserve stacks and that they are going to get the feed. A smart Annie player is hungry for kills, but is not reckless. It may take practice, but an Annie with a few stacks of Soulstealer is terrifying and is highly likely to make the enemy team surrender.

When building a Rod of Ages (which I would usually get right after Soulstealer, however some situations involve it before), the item you get to build it depends on how the game is going. If you are being smart, have 1 or 2 stacks and are in no threat of dying, get the blasting wand...don't bother getting the Catalyst as it doesn't help to benefit your damage. If you are taking frequent damage and are worried for your survivability, then get the Catalyst when building the Rod.

If you want to build a Rylai's Crystal Septre for a little more durability as well as as the slow, I suppose it's alright if you want to sacrifice the Rabadon's Deathcap. I just like the extreme ability power boost since I typically am very cautious and am never in any real danger for more durability unless my team is ******ed and fed the enemies.

Late game items are fairly variable. My games usually end before I can even get the Deathcap. I would always recommend the Doran's Ring, Sorcerer's Boots, Mejai's Soulstealer and Rod of Ages. After that you can basically build on how the game is going. If you feel that you are dominating them and have plenty of stacks, get the Deathcap right after RoA. If your game is fairly even, then you might want to get the Banshee's Veil for a little more survivability. I like the Void Staff just for that magic penetration because it makes my cry-inducing damage all the more powerful.

Many people would prefer starting with W (incinerate) in the beginning of the game so that they can build up their stun on the home spawn and go to their lane/mid. I wouldn't recommend this because 1)If you are soloing mid/top, incinerate does barely any damage at level 1 and you will not get a second one off, even with the 2 second stun, and 2)Even if you go to a side lane and manage to stun both of the enemies with W, you and your partner most likely do not have enough damage output to kill one of them before they can get to their turret. Because of this, I like to start with Q. Q has much more damage output at level 1, even though you won't be able to build a stun, and you can start farming minions immediately when they come.

Lots of people would rather save Molten Shield to level last and not bother putting a point into it until late game. Molten Shield is extremely useful because even though that armor and magic resistance isn't too fantastic, it still damages attackers which is still great. Also, it is a very cheap mana-cost spell that will help you build your stun up faster. I always get Molten Shield at level 4.

One fantastic thing about Annie is that she is very versatile. She can solo mid, top, or lane with a partner. My build is concerning casual play, not tournament play, so don't rage about my philosophies. I prefer to lane with a partner as Annie, particularly a friend who I can verbally communicate with to coordinate ganks with them. In early game, your job is to just farm. Because your mana is refunded if your disintegrate kills the target, you have almost no mana issues early game. Don't bother wasting your Q on enemy players unless they are overly-aggressive and you need to get them to back off. However, you can coordinate kills with your laning partner as early as level 1. Just keep using your Q to farm minions. Whenever your stun is up, I like to Q an enemy and use incinerate and quickly run away just to remind them that you're no food.

This is where Annie really starts to shine. This is also the part of the game where people start to complain "OH ANNIE IS SO OP!!" and you will get a couple instant victories at 20 minutes in ;). When there is an Annie on the other team running around with her stun up and Tibbers ready, you had best be frightened. This is a key part to playing Annie. NEVER use Tibbers unless your stun is up, apart from a rare occasion: you just blew your stun and the enemy is at such low health that the damage from summoning Tibbers is enough to kill them as they run away. Remember that Annie hits like a truck, so landing that perfect ultimate that gets 3 or 4 enemies and stunning them, followed by an incinerate is so satisfying and almost guarantees your team a kill if you're not alone. You never want to be running around in the front lines, even if your stun is up. That's the tank's job. Plus by this time you should have a few kills and Mejai's...don't lose your stacks to something stupid.

Assuming that you have a Mejai's and are somewhat decent with Annie and have a somewhat decent team, you should ideally have a fair ammount of kills and a decent-high ammount of stacks. Annie is one of the easiest characters to get 20 stacks with because even without a Mejai's, you do ridiculous amounts of damage. But those stacks just fuel the fire (no pun intended) that gets her rolling. You should always have your stun up wherever you are, unless your team just finished a team fight. You never know when that next team fight will begin or if you could be ganked. If you do get ganked, use Q if it's a single person, hopefully you can use W if it's more than one target, however, using Tibbers to avoid a gank is acceptable to preserve those stacks. In a teamfight, just wait for everyone to bunch up and pop Tibbers right in the middle. They take ridiculous damage, are stunned for 2 seconds, and you are free to use W and Q. You are almost guaranteed a kill from the start, assuming you have lots of stacks and the enemy team is very magic resistant.

Hopefully this guide will help you to be an awesome Annie player. This is also my first build so feel free to give suggestions or ask any questions that you may have about Annie :D