OK. So here is my first guide on one of my favorite champions. Malphite is one of my main champs because of his mass durability Solo top and in the Jungle.
This build may seem a little unconventional, but it works wonders.

Pros

Passive Sheild
high early harrass damage with Q
High durability
high movement speed
Not easily countered

Cons

Predictable
Ignorable
Vulnerable to Ability Power Champions

The items in this guide are very bulky and defensive. It can be altered to fit you immediate needs and the enemy team. You can change out any of the items for a Forc of Nature if the enmy team is AP heavy.
I take thormail in both builds because it alows you to jump in and focus the AD carry without them doing much to the rest of your team.
Frozen Heart is a great item in alot of malphite builds becasue he has slight mana problems without blue buff and in the early game.
You can also take a Saphirre chrystal to counter-act your mana costs.

SOLO TOP
When Soloing top take your Q first to gain early harrass on your apponent who most likely cant take the constant damage from your Q.

After your Q grab your E which will prevent you apponent from harrassing you at melee range because of the high damage that can be put out with your E.

Max your Q then your E because you W isnt going to help you alot in the lane unless they constantly are harrassing you.

Q,E,R,W

JUNGLE
When in the Jungle take your E first to deal massive damage to all of the minions of the chosen camp.

After Your E take W to deal that extra damage against the nuetral camps.

Take your Q last because while Jungleing, it wil only be usefull for ganking and counter jungleing.

E,W,R,Q

In both builds max your R whenever possible.

Solo Top
Exhaust is a good addition to you kit when on top because if you move in for the kill they cannot flee the fight. The movement speed Steroid on his Q allows for easy 1v1's

Ignite is there in combonation with exhause for the best possibility for the win during a 1v1.

ALTERNATES
Alternate summoner spells can be substituded for any player preference.
Flash is a good sub with the fact you can Flash ult over walls. Along with the distance in your ult. You can easily catch up or run away.

The only other alternate Sumoner would be Teleport, but only if you know there will be allied wards spread around the map.

In a team fight situation you want to be the initiator and the cleanup crew. If you see an enemy fleeing the scene Q to slow and kill them.
You want to focuse on disrupting anyone who looks like they are headed to your squishies. Even though you do good damage your carries are doing most of the damage.
To be succesfull in a teamfight try and save your ultimate instead of useing it to initiate. if you have to initiate with your ultimate do so. Because the last thing you need are peole complaning about how you didnt use you ulti. If you save your ultimate instead of initiating with it, use it do counter channeled abilities.