This guide is mainly an experiment that I have going with a few AP based Champs. Heimerdinger is an amazing Champion that if you can use him with skill and some common sense, you will give your team the defense and ability to move around the field freely without the need to go B (back or base) every time a minion wave comes near a turret or a solo champ thinks its smart to BD (backdoor) a turret. THIS GUIDE WILL NOT GUARANTEE YOUR VICTORY.... BUT it sure as hell kicks some *** if played well. I have yet to fail with this build but trust me, this build is only possible if you have a good laning partner who will support you when the time is needed. As always, it impossible to be great and win without a good team and trust me, Heimerdinger is not a pusher. If you have found a way to make him a pusher please do tell.

Heimerdinger uses magic damage so it would only be ideal to use Greater Mark of Insight for its +0.95 magic penetration.

If you have played Heimerdinger before you will know that he is frequently OOM (out of mana), so using Great Seal of Clarity will give you a fair amount of Mana Regen that you will need to keep the fight going when it is at its worse with its +0.065 mana regen per level which comes out to be 1.17 mana/ 5sec @ level 18.

As always, he who uses his abilities wisely or most often shall win the fight!.. So the use of Greater Glyph of Focus gives you the chance to have a much better CD (cooldown) rate which allows you to get that good push going and a frequent series of stuns. Greater Glyph of Focus give you a very useful +0.65 CD reduction.

With the Quintessence I used three different Runes to help give a wide variety of bonuses that can be very useful.
As everyone can tell, Heimerdinger is EXTREMELY slow early game, and most of the mid and late game also. So I have chosen Greater Quintessence of Swiftness to give him that shove on his way to a good sprint. This Quintessence gives Heimerdinger +1.5 Movement Speed.
Greater Quintessence of Wisdom is a simple win within itself. Heimerdinger is going to be getting ALOT of minion kills due to his turrets. So a nice little boast in exp. is fantastic. Greater Quintessence of Wisdom gives Heimerdinger +2% exp. gained.
And the final Greater Quintessence I chose to use is the Quintessence of Celerity. This is once again a great CD Reduction and I believe that Heimerdinger's stun can be very useful and this will give it more capabilities to be used in team fights with a 2.34 CD Reduction at level 18.

The Masteries I have set up for Heimerdinger for this build are common for many AP and Mana dependent. These masteries give you a good boast to your mana pool and also to your mana regen. You are given a good boast to your movement speed also which is very important due to the fact that Heimerdinger is SO slow. Also there are the cooldown masteries which are VERY important to the team during team fights and ganks/protecting from ganks. Having the ability to use Heimerdinger's turrets over and over again for retreats and for supporting the team mid fight is extremely important and the main reason Heimerdinger has his turrets.

Heimerdinger is AMAZING with AP and I do believe that adding a huge chunk of HP in there makes him very amazing even though he lacks the Armour to take a lot of damage.
The lifesteal is that extra little treat that I added to give you that chance to stay alive in team battles. But i highly doubt you will have a game that lasts long enough for you to get Hextech.

Ghost is a MUST Heimerdinger is EXTREMELY slow and the Ghost spell will allow him to just GTFO when all hell breaks loose, and trust me everyone will focus Heimerdinger due to his stuns, turrets and because he is s squishy.

Flash gives you that chance to jump over walls or to chase down that annoying guy who is running away and you just want to stun and get him for that nice ks. Flash is going to be amazing if used right.

Farming is going to be a very important factor when using Heimerdinger. Heimerdinger is not going to be expected to get a lot of kills, just support the team and move on turrets. Farming minions is going to be the best way to rack up the money needed to make this build. Using you turrets to form a wall is ideal for Heimerdinger and this is a must to progress well with your teammates. Early game using the turret will be the best way to get minion kills due to Heimerdinger's low mana pool. Mid game and late game, the turrets level up to level 5 will be very powerful and will easily kill full minion waves. Also, your mini-rockets (W) and your Grenade (E) are very powerful when it comes to clearing minions. Using Heimerdinger's Ulti (R) is not advised for clearing minions due to the fact that it should be reserved for team fights and retreating.

If you have any other thoughts for future guides please let me know. Comment and vote my guide up or down depending on who useful he was for you.
Heimerdinger is an amazing Champion but completely useless if you don't have an understanding of the game play and teamwork.