Flash - Most useful escape tool. Can be used on the offense, very sparingly and only when you can ensure a kill otherwise save it.
Ignite - Use as a last resort when spells are on cd's or when you need to get as much damage out as possible. If there are any champions like Volibear, Mundo or Swain that heal it can be a useful tool to half the effect.

So basically everyone is looking at Anivia as one of the big mages, certainly had a place in the season two finals, being banned out in the majority of the semi finals. Interestingly always by the team with second pick. His a skillful champ to use, I didn't see him get used much in low elo games. I've been playing Anivia ever since the price reduction from 6300 -> 3150. I hated him at first and absolutely regretted buying him until I became good at landing the stuns and placing the walls then I found he was my strongest champion and among the most fun to play. I am noting that this build is very different from the tournament builds. The build isn't as important as the skill factor of a player and ideal builds are going to change depending on the role in your team. I've probably played Anivia for hundreds of games and I've adapted the build and tried to maintain the core AP mid stats like AP,CD reduction, Mana, M.regen as my main focus. The worst Anivia I have ever seen play was my friend that I was trying to convince to play the game. Sequencing a level one wall then spamming recall probably won't help in a crisis. It certainly didn't for my friend.

Generally the build remains pretty standard however, I would change certain items to counter certain champions. If there is a strong Karthus, Fizz, Brand then I will grab Zhonya's Hourglass instead of a second Rabadon's Deathcap to negate their ultimates, it's so simple and easy. In the case of Lux, Ziggs... Any champion that is likely to try snake blue with their ultimates I will negate this by pink warding blue to ensure they don't know when its nearly dead. They can send blind fire at it, goodluck with that.

My reason behind grabbing the banshee's veil is that it feeds into my mana pool, boosts the AP bonus on Archangels. Stops most assassins from jumping at you, however not much you can do about an Ahri or Leblanc jump that won't be countered. However it stomps on most of the AP champs that require a combo on you like Leblanc disabling Q + R Combo's that require two spells to achieve double damage.

Deathfire alone will grant 15% cd reduction, whilst blue is 20%? on the mastery page I've already grabbed 4% and I think it caps out at 40% (not too sure) but it is a safe assumption that you probably don't need any more cd reduction if you can keep blue on yourself, keep it warded if necessary, it is very costly if it's stolen by the other team. Not only will you not have the mana in group fights but you will also see it when your CS is about 20 lower than it should be not to mention experience you're lacking because you can't fund mana for killing golems or wraiths.

In my build I don't grab wall until fairly mid game. I feel it's more necessary in team fights or when you have an ultimate down, additionally level 1's wall alone will probably not block or inhibit anybody by much and instead just waste a ton of mana. Hence Anivia is thirsty, he wants his mana for taking golems and wraiths.

Stun run, Lay ultis down to slow, wall foes away or trap them near you. You decide skill sequence however standard is to chuck an ulti down, stun them inside it and wall them in it for longer then flash damage with E. Once I have deathfire, its fairly noteable that Q has 1100 range and deathfire doesn't nearly have that much so use it when you're in range its going to be fairly situational in a fight and is crucial to winning. If you can drop that AD carry quickly then I find half the time I am kiting an assassin of some sort while the rest of the team is 4v3, good odds of winning.

Jungler is always going to give you 2nd, 3rd, 4th.. blue however, Anivia is strong enough to solo blue when about lvl 10 with half mana. Shouldn't be too much of a problem. If they steal your blue, go grab their blue. Too simple. Take the golems and wraiths

Respawn time's 5m on blue, 1m40s on wraiths and golems.
6m on dragon, 7m on baron. being mid lane and generally having the highest cs in game you'll be expected to ward baron maybe when support isn't able to be everywhere at once.

Flat m.res glyphs because most magic damage you take will be in laning phase. A stronger early game leads to a stronger end game. Feel free to take the ones that max out at level 18 if you feel it suits a certain team comp.
I've grabbed movement speed because I like to kite, I need to get around the map quick if i want to save allies with my stuns, walls, slow.
M.pen on marks is just superior to getting AP, thank you other forums for working that out for me.
M.reg seals because you're a thirsty anivia.

Pro's:
Easy to kite enemies that don't jump, stunlock you.
Huge burst damage and sustain from ulti. *Note most mages don't have both a burst and sustain.
The walls can manipulate who can fight you by blocking them with you or away from you and your team. This allows you to choose the battles.
Almost indestructible if you egg in a safe place under the turret. This frustrates most mages, I've even been called a cheat.
Con's:
Super Squish.
Mana Thirsty.
Skillshot's aren't brilliant for beginners.
Do not use Anivia if you're lagging. he get's destroyed.
Egg takes a lot of damage from AP. When the mage has spells after you've been egged there is not a great deal you can do because its like double damage or something.