Well, here it is. A very uncommon champion from my experience. As well as an extraordinary jungler and ganker. If you're not already a fan of Maokai I have one question : Why did you look this build up? Anyways, if you enjoy ganking and almost always getting a kill out of it, jungle Maokai is the way to go.
Smite is a must. You're jungling. End of story.
Flash is my other spell next to Smite. I prefer it to Ghost because I get Shurelya's Reverie anyways. It's useful for chasing others who have Flash also, in addition to flashing over walls to get away.
Ghost is another option. Extra speed to close gaps. I'm not that big on it.
I don't really recommend anything else. You're always welcome to try something like Exhaust or even the new and improved Heal.
Okay, I'll be honest; I'm terrible with the names of the runes and I'm way to lazy to look them up. So, with that being said, I will just say the type of rune and what it gives. I will also try to give more than one option for diversity. Keep in mind this is what I recommend, you may want something entirely different. I also put them in order based on priority; the higher in each section, the more I recommend it.
Flat AP - The extra 15AP boosts my damage just enough to make my jungling more efficient.
Flat HP - Extra HP is always nice for jungling. It could be useful, but I don't like it that much because I get Doran's Ring to start.
Atk Spd - Not what I recommend, but always an option.
Flat Armor - I like these as opposed to Magic Penetration because they are almost as good as their seal counterparts
M Pen - Always nice to have a little more magic penetration to do a little extra damage.
Flat Armor - No brainer. Makes jungling about 10% easier because of the extra armor.
Dodge - Always an option. If you dodge more than thrice from Golem/Lizard, you will have blocked more damage than you would have with flat armor seals.
Flat Magic Resist - These do not help with jungling, but I like them because Maokai does not recieve Magic Resist per level.
Flat AP - Some more extra AP never hurt.
Now I could go into detail about why I put each point where I did, but that would just be a wall of text no one would want to read.
However, my 0/21/9 mastery build's target is to reduce as much damage as possible while jungling as well as in team fights where those extra points in Defense could mean life or death. After all, you should be at least tanky. The reason I put my last 9 points into Utility and not Attack is that I would rather have more mana regeneration and a tad longer buff duration than 4AP and some magic penetration I do not need.
So, on to items.
It may sound strange, but I like to start with Doran's Ring. Cloth Armor and some extra health is always nice, but I don't really need it with my runes and masteries. On my first back from the jungle, I have two options; I can wait for boots or I can gank an overpushed lane. After my first successful gank, I have enough for Philosopher Stone and Boots of Speed. Then I really just run around, gank, and jungle. I buy items based on the other team. If they have tons of AD, I get Sunfire Cape or Frozen Heart. If they have many Casters, I get Force of Nature or Banshee's Veil.
Okay for starters, Q = Arcase Smash, W = Twisted Advance, E = Sapling Toss, and R = Vengeful Maelstrom.
I start off with E at level one because it provides the most damage potential when starting at wolves. By level 3 I have one point in all three of my spell, getting my Q at level 2. Having Q and W ensures I have the maximum CC'ing potential with a snare and slow but also having some damage from my E. I max W first to increase the snaring duration and give my teammates more time to deal damage. I max Q after for a stronger slow. The only reason I get E in the beginning is for an easier time jungling and leveling up to level 2. Like with most champions, I take a point in my ultimate whenever I can.
I skip over both the buffs and just do wolves, wraiths, and golems, in that order. At the start, I grab my Sapling Toss and throw two saplings in the base to get 2 stacks on my passive. (You don't have to do this. Maybe just tell your team to use a couple spells to get your passive.) After I do this, I walk to the wolves and wait until 1:05 to start throwing saplings down where the wolves spawn. (Keep in mind that saplings only last 35 seconds.) After I take down wolves, I run immediately to wraiths and smite the big wraith. I attack each of the three little wraiths once, throw a sapling on them, and use Arcane Smash. Then I run directly to golems and kill them spamming my spells. After they are killed, I am level 3 and have one point in each skill. After this, I go back. However, I will be just shy of buying boots. From here you have two options, you can either wait for around 25 gold or run to a lane and gank.
I always run to a lane and gank. Generally speaking, I do not need boots becuase I have the element of surprise and Twisted Advance. Remember, ganking and getting gold for your team is more important than being a couple levels higher than everyone else. I mean to say you should always try to help your team even if you have to skip over a neutral minion camp.
Yes, I have a section for this. To initiate, I ping who my target is. (It may sound dumb, but in solo queue, pings are important when you don't have enough time to type.) After that, I run in and use Twisted Advance. I throw my sapling on them to ensure the damage from exploding and landing on them. From here, I run behind my target and use Arcane Smash to give them a little push backwards towards my teammate. If they haven't died yet, I use my ultimate in front of where they're running. Some people will try to stay out of the circle, causing them to take a longer route to run away. My ultimate is more to try and make the target change their path, rather than do more damage. Be sure to use your Shurelya's! That extra speed helps you and your teammate secure the intended kill.
All in all, if you want a well rounded jungler, team fighter, and ganker, Maokai is your man. (Well, he's actually a tree, but yea.) The ganking is amazing, the jungling is relatively easy, and Maokai is a damn tree! And after you get Sunfire Cape, as Phreak says, "No one's stopping this forest fire!"