Maokai is an awesome combination of AP damage, support and tank.
If you build/play him correctly, you can fill all three roles effectively and lead your team to victory.

Important things to know:

• is nearly your entire early game (farming, harassing and scouting).
• has a very short cool down and can be used situationally.
• can be used to escape.

This build focuses on HP, AP, MR and armor. The intention is for AP, MR and Armor to be above 200 at end game and for HP to be over 3000. We also grab a couple helpful auras to help our primary damage dealers do their job.

For runes, we take a combination of utility, defensive and offensive focuses by using: magic pen marks, mana regeneration seals, magic resist glyphs and flat health quints.

For masteries, we take the standard caster 9/0/21, making sure to pick up imp clarity for more support utility.

This allows us to stay in lane longer early game and harass/farm as much as possible.

Core Build

Let The Games Begin

Starting the game, I like to get a jump start on my core build by buying a Sapphire Crystal. This also allows me to get potions (extremely helpful early game). However, there is nothing wrong with getting Doran's Ring instead if it matches your play style better.

First Return Home

Catalyst the Protector x2-3
The first time you return to base, you should be buying your catalyst (this item is OP) and boots. The catalyst provides a lot of staying power in lane. If you have any left over gold. spend it on mana and health potions ( mana > health because of your passive). Don't hesitate to grab a ward if you can afford it either (your saplings don't last very long and if you place a ward, then you can use the mana to farm or harass).

Mid Game

Throughout mid game (after lane phase) you will need to return several times. When you do, focus on finishing your RoA and boots, then work on your AotL last. This will give your RoA the time it needs to get maxed out before end game.

Late - End Game

As the game is reaching its end, you need to finish your build. First order of business is survivability (you need to tank). Buy a negatron cloak and a chain vest for your armor and mr. Then upgrade your cloak into an abyssal scepter and buy another negatron cloak. At this point, upgrade your chain vest into a thornmail and your negatron cloak into a banshee's or Force of Nature to finish the build.

If the game goes any further, just buy elixirs.

Your Role

With this build, you are wearing several hats (damage, tank and support) but your top priority is the safety of your primary damage dealers. If they die, it is not likely that you will win a team fight.

The Team Fight

Just before a team fight breaks out, there is often a standoff between both teams.
During this time, you have three major jobs:

1. Harass (throw saplings at enemies)
2. Scout (throw saplings in the bushes around you)
3. Block missile fire (jump in front of missile attacks, if they would otherwise hit a less beefy champ)

This can go on for some time, but eventually either one team will back down or a fight will break out.

When the fight breaks out, drop your ult immediately in the primary fight zone. Your primary goal at this point is to reduce the damage your team will be receiving. Then look for the first focus or biggest threat and root them down with your W spell (immediately following up with your Q and E). Rinse and repeat until clean. Lastly ignite your ult for MAXIMUM DAMAGE!!