So, starting with the items, i usually start with pendant, and one health potion. Pendant, is now half way to philo stone, and it gives you great sustain while jungling. Adding a good pull, you can finish blue, without loosing almost any health. You wont need the potion, if you do everything right, atleast, I dont need it, but I still recommend it, for improvising situations, such as bad pulls, and/or distractions while jungling, and those stuff, aand, when ganking.
I folow up immediatly to philosopher, and boots 1. Philosopher is going to give me even more sustain, and the incredible GP10, and the boots, will give me some more movement, which is going to help a lot ganking. Then, I follow up to heart of gold, which gives me +200 health ( and thats great for maokai ) and even more GP10 ( I love those items. )
And then, finally, I finish my boots, which I prefer mercury, because of MR and tenacity.
As maokai's extremly mana hungry, frozen heart is going to give us more armor and mana. I build maokai as an AP/Tank/Support, and he's going to deal some damage, tank A LOT, and I usually leave the kills for the carry. Then I follow up to rod of ages, thats going to give me more HP, Mana, and ability power. Such as an great item for maokai. After that, I pick zhonyas, because it gives you more armor, AP, and its active its extremly great. I usually engage teamfights, pop up ulti, prepare passive, and make them focus me. When im low HP, i pop up zhonyas, so they gotta focus other one, and when it ends, I use my passive ( Heal lots of HP ) and finish my ulti ( Because of its damage absorved ) it deals tons of dmg, combining with ability power. I finish my shurelyas. Its still gives me the regeneration, and its active is extremly helpfull. Then I follow up my randuins, and it gives you more armor and that stuff.

Situationally, if you need more MR, you can replace Shurelyas, randuins or frozen heart, for items like: Spirit visage, Guardian Angel, force of the nature etc ..

For summoner spells, I take those up there. You can change flash for exhaust, ghost, or even ignite ( in my opinion ) but I dont find it viable. I always like that flash, to cross walls and that. I dont recommend you to replace smite.

The way I jungle is, wolves --> blue --> wraits --> red --> gank bot ( for early and unexpected first blood ) --> golems --> wolves ( and then repeat )

If it goes bad

Wolves --> blue --> wraits --> wolves --> Red --> Gank ( any lane ) --> golems --> wolves --> repat.

You dont have to do it that order, and probabily I dont to it every single time. But I still recommend it. Gank every lane, make pressure, throw your E when passing by a lane, so they'll think you're going to gank.

PS: NEVER STEAL OTHER LANES FARM.
I'm tired of seeing junglers, after gank ( when not pushing ) stealing their farm, and you souldnt do it.

If you want, you can take a look at my stats with it, I screenshot it from lolking.

Sadly, I havent print my other scores, which were better, but these are still very good.

For ganking, you have 2 options: Engage, or let your teammate engage. It will always depend from who your player is, and which champion hes playing. I usually let them engage, then appear from the back, pop ulti ( when the fight is going on ) use W, immediatly use E, and when W's effects over, use Q ( MUST BE NEAR HIM ) so you can make him loose some much time, and he wont scape. If he does, E's CD is reseted, and you can always throw it again, if he scapes low HP. If he doesnt, Chase him with W, and there is no second chance for him. *DO NOT OVEREXTEND*