As a Maokai main I'm constantly trying to find the best ways to play him. Maokai used to not be very meta, for a long time. He just didn't fit in; couldn't take towers early, and with no MR scaling he was just outdated. With his updates he's not only META again, he's pretty strong. "The top three tank champs right now, in my opinion, is Ekko, Poppy, and Maokai." - Dyrus

While he was weak I started playing him jungle, and I slowly figured out how to do it. I couldn't carry a game as Maokai top, but I could make a big difference with Maokai jungle. So if you'd please, give this a try. :)

(NOTE: I am still playing with this build and improving it, so there will be changes to this page as I figure it out more. Comment with if you've tried the build and tell me how you think it could be improved.)

Your first jungle clear should go a little something like this.
Head to where the gromp spawns, and at 1:00 start spamming your E until it spawns (you should be able to get 4 down). Smite and kill Gromp, then take a point in Q. Head to Blue and kill it. Do not worry about conserving mana, spam your Q and E constantly, that is how you must clear. After Blue go to Red, smiting it. You may have enough health left to take Krugs, but it is quite risky. If you still want more gold but don't want to fight krugs, venture to river and take scuttle.

Some tips for farming as game goes on:
~Always initiate on the camp with your E; it has the longest cast animation and if you cast it after you start fighting you spend time tossing your E instead of attacking the camp. Try Eing after you Q too, because of the knock-back.

~You can use your E and W in succession to jump over short walls, most notably krugs. Toss your E and IMMEDIATELY W onto the monster before you E hits. If your E hits the camp will aggro and you will not be in W range. This is sometimes wonky to pull off, and takes practice.

~Reposition yourself closer to the monster after each Q to keep it in knock-back range. While the monster is knocked back you can get 1-2 basic attacks in during that time, or toss an E without getting hit. Simply step closer to monster before you Q; this is most useful on big camps.

~DO NOT GANK UNTIL YOU GET SKIRMISHER'S SABRE. It makes you significantly more effective, if you gank before then you're wasting time you could be farming. Just farm a lot, and gank lanes with good opportunities. If you spend too much time ganking you will not be as effective in the team-fight phase; which is when you should be strongest.

Resolve:
~Runic Armor increases his passive healing, along with spirit visage, it's a life-saver. (also increases jungle item lifesteal, improving sustain)
~Maokai does not need Perseverance, so Insight provides a consistent Smite (objective control) and Flash (which is very good for him).
~Maokai is a utility team-fighter tank; which is why Legendary Guardian is the obvious choice.
~Strength of the Ages is important because he needs health early, this keystone provides that.

Cunning:
~Maokai doesn't need the slight damage of Savagery, so the Wanderer is a much better option; it gives him map mobility and gets him to the teamfights.
~Although at times you'll find yourself low on mana, you do enough damage to make Merciless effective.

The thing with Maokai is, he's got a lot of wood. So you need to have a lot of wood when you play him. Go in, displace the team, and win your team the team-fights. Be tenacious and keep getting your basic attacks off, you'll probably survive due to your passive; and get more kills and assists along the way. Maokai is a great engager, although you can't burst most people down, you are still a play-maker. Force your team to be a badass with you. Keep in mind, you are a utility team-fight tank. So when teamfight phase rolls around, always make sure you are there; you can make a huge difference! You're not a split pusher or assassin so stick with your team, lock down people who threaten your carries, and have a GG.

Some Parting Tips:
~Maokai is strongest when he his flash is up:
"The power spikes of Maokai is when you... or, the times you want to do stuff is when you have flash, basically. When you don't have flash you're not as strong, but when you have flash you can force plays on people..." - Dyrus
So you can flash W over a wall, or catch up to a fleeing enemy, or go for a long-distance ingage; really get into the team and start tearing **** up.

~Always ult shortly before you go in or before the enemy team engages on you. If you wait you could very well get stunned before you can R or bursted by damage you didn't expect. This may seem obvious but the amount of times I've died or my teammates have died because of me not ulting in time is far too often.

~When you are ulting remember to keep your teammates in the ult range. All friendlies in it take 20% less damage (except tower damage). So if you keep your carries in the circle you will increase the likelihood of winning the fight by a good bit.

~When ganking tossing your E behind them is often better, it will probably hit them and slow them, allowing you to finish the job. Throw it where you think they will run.

~Your E are great for vision and has a long range. They don't do that much damage, so instead of throwing it at Dragon when you're killing it, throw it over the wall for vision; it might just stop them from stealing ;).

~When you use W on a scuttlecrab, it can't move so long as you say still. (If you Q it will be displaced and can move again)

~You can use your W to avoid skill shots if timed right, and even avoid thing such as Karthus ult!

~Use your Q to stop channeled abilities! The displacement will stop things like teleport.