Malzahar is typically built as an AP champion, and as such, the AD aspects of him are often overlooked. Although he has no main abilities that gain bonuses off of Attack Damage, Malzahar's passive, Summon Voidling, gets bonus AD based on 100% of Malzahar's total AD. The increase in damage can not be found in the tool tip or the voidling's stats when targeting it, but can only be seen by watching the damage it deals. While building AD Malzahar, important things to note are that it does not benifit from Malzahar's attack speed. This makes attack speed a stat you may want to avoid, although it does help your own basic attacks.

Items that are generally good on Malzahar are pure damage items. I find that Manumane and Black Cleaver are important on AD Malzahar because the bonus mana allows for more spamming of spells to max out the voidling passive while the Black Cleaver's cooldown reduction and armor debuff benefit the voidling and your spamming. An important thing to note when building items for AD Malzahar is that your voidling is considered a minion and does not count as a single target spell nor does it apply on hit effects. Banner of command does affect the voidling and Shard of True ice can also target the voidling.

Good items:

Boots of Lucidity (Cooldown Reduction)
Manumane (Mana and Damage)
Black Cleaver (Damage, Cooldown Reduction, and Armor Debuff)
Maw of Malmortius (Damage, Magic Resist)
?Infinity Edge? (Damage) - When I learn more about Voidlings and Crit I can confirm this.

Starting with Call of the Void allows for generation of voidlings quickly, even before the match has started. However, from there, maxing out Malefic Visions reduces its cooldown and allows for target control with your voidling. When Ulting, make sure you have a voidling up or will have one up so that you can lock down an enemy while your voidling attacks. A full combo can generate a full voidling, allowing 2 voidlings to be out during your ult at a time if done correctly. to It is important to keep in mind that although your Null Zone does not scale off of AD, it still deals percent health damage, increasing the importance of locking opponents in your Null Zone when you ult.

Starting with Call of the Void and generating 3 stacks of Summon Voidling before 1 minute in allows you to use your final spell to summon the voidling at 1:41. At this time stamp, the voidling will be fully enraged and, provided it is the closest target, can be a really good tank for your jungler. Do it. Save him some health pots. Make him want to gank for you.

Voidlings can tank turrets, although if your Malefic Visions is on the opponent, the turret will switch to you. This is important when pushing and your minion wave runs low or when taking a turret without a minion wave. Just spawn a voidling to increase the duration the turret does not target you. Also use this when diving with no minions as it allows you to get into the turret before it targets you. Although do note that that the turret will focus your voidling so fighting under the turret has a great chance of killing off your voidling before it can do damage. Voidlings can damage the turret.

Keeping 3 stacks of Summon Voidling wherever you go is incredibly important. Play as if you were utilizing Annie's Stun.

Although it is not the best item, applying Shard of True Ice onto a voidling increases its chasing potential

Almost all of these tactics are useful as AP Malzahar as well! Keep that in mind!

Summon Voidling gets 20 + 5(Champion Level) BASE attack damage and 200 + 50(Champion Level) BASE health. The Voidling receives 100% total AD from Malzahar as bonus damage. Keep in mind, the AD bonus to the voidling is NOT displayed in the tooltip nor can be seen by targeting the minion in game! But trust me, it is there and it is applied.

The voidling enrages after 7 seconds giving it 50% increased BASE damage and armor. At 14 seconds, it gains 100% attack speed. Later in the game, the 7 second enrage is not nearly as important as the 14 second enrage.

With voidlings lasting 21 seconds, it is possible to get a maximum of 3 out at a time, although maybe only for a short duration.

To sum it all up, Malzahar can get his attack damage applied to targets from 4 different units at most (counting himself) making AD Malzahar pretty strong and overlooked. Although his voidlings dont gain attack speed and items for them are difficult to find, he can be pretty strong. My mind is still open to adjustments for this guide as I test out builds and receive feed back from comments. Please share your (mature) thoughts!

Things i still need to find out that I will update the guide for when I discover the answers:

Can voidlings crit?
Does Malzahar's Armor Penetration effect the vodilings?