Hello and welcome to my Diana jungle guide. Diana jungle becomes the role of a ap/tank with awesome ganking power when used right. This guild will show you the best way to build her in the jungle.
PS. since diana is not out on the public servers yet. you will not be able to see the skills yet i will update the guide with skill prios when she is realeased on mobafire.
Edit- i have an updated guide, cheak it out :)

I have chosen these runes because attack speed runes will trigger her passive quicker and since her passive does aoe damage and scales from ap, the quints help with all her ability and passive. The Armour runes are standed jungle seals and i use ap glyphs for that extra damage and faster jungle route. These are good runes to use to help clear the jungle quickest

The masteries i have chosen to use are to reduce damage taken whilst jungling and getting the most potention whilst ganking. The defense tree i have put the points into damage reduction and in the support tree i have put points into increased mana and movment speed along with increased buff duration to help ganks. I have put my last 4 points into the offensive tree to gain an extra 4 ability power to help clear the jungle just that little bit faster, but them 4 points can realy go into anything else you prefer.

I start the game with boots and 3 health potions because the boots will help ganking and faster jungle routes, and with the masteries i have chosen 3 health pots will get you through the jungle with ease. I then go back after 1 gank or if none after 2nd wolves and buy towards a rod of ages. NOTE that if you get first blood or a kill and CAN afford a blasting wand, get it and skip the ruby crystal. It will help you a lot. After a couple of ganks and jungle routes go back boots and then repeat until you get your rod of ages.
The tier 2 boots you buy depend completely on the enemy team setup. so buy whatever counters them the most.
After you have bought your boots and rod of ages, do a couple of more jungle routes and ganks until you have enough for another blasting wand. If you notice when your ganking you are taking a lot of damage or even dieing, but a giant belt instead, upgrade this to a rylai's as soon as you can.
After Rylai's you should be trying to get a deathcap fast, after you get deathcap you become very very strong.
Then by a nashors tooth to increase the amount of times your passive activates along with gaining some ability power aswell.
Finish it off with a item of your choice, if you a carrying your team try and get a zonyas or another dmg item, if you seem to be dieing alot then purches a gaurdian angel or even a warmogs.

The skill sequence for diana is very simple, you want to level your w first which gives you a shield when active and then another shield shortly after if all orbs deal dmg. This is an extreamly powerful ability when jungling at level 1, it allows you to kill blue+wolves+wraiths+goloms with only 1 health pot. At level 2 you want to level your q to do damage to your opponent and to clear the jungle fastest. At level 3 grab your w again to be able to kill red buff without a healthpot. Finally at level 4 grab your e and start ganking and prioritise your q ->w ->e leveling your ultimate at 6,11 and 16.

Obiously as a jungler smite is your best friend unless you play shaco ofc, but i believe that smite and flash is the best this to use as Diana because smite will help you through the jungle and for stealing global buffs of your opponent. Flash is usfull to kill or to not be killed, you can use it whichever way but it is a all around good summoner spell to use.

Passive- every 3 basic attacks you will deal extra damage based on your ability power. This is very strong and is extreamly helpful when clearing the jungle.
Ability Q- your q fires in a curve towards your curser location and deals damage and affects the targets hit with moonlight. This ability does damage to every enemy hit by it so is very strong AOE for the jungle.
Ability w - your w is a shield that will shield you on use and summons 3 orbs around you that circle around and when hit an enemy will deal damage, when the third orb hits it will refresh the shield. This ability is the extreamly strong in the jungle and is worth getting at level 1.
Ability e- Your e will pull all enemys in a radius around you towards your and slow them. This is a awesome ganking ability but deals no damage so getting it once at level 4.

The best jungle route to do with Diana is starting at Blue with a leach of your mid, basic attack until blue aggros onto you and then use your w, keep basic attacking untill he as at 450 health then use smite to finish it off. Level your q and then head to wolves q whilst you a running there to pull them, once they attack you use your w and then basic attacks and another q to finish them off. Head to wraiths and do the same using your q and w with your basic attacks actaviating your passive to kill wraiths extreamly quick. Move on over to goloms and q in between them to hit them both, the activate your w whilst basic attacking the small golom. finish the big one with another q and basic attacks. head to red by this time your smite should be off CD. use your q to engage and then w, smite it and then use another q and w combo to finish it off. Wraiths should have just spawned so head over to them and standing ontop of them and activate your q into w and basic attacks to get level 4 in a respectable time. level your e and start ganking.

How do you gank as Diana you might ask? Well its rather easy actualy. Before actualy ganking make sure there are no wards anywere, if there are either go back to jungling or get your support to destroy them or even go a different way. But when you are actualy going for a gank you want to use your Q first then start to basic attack them, if they seem to be getting away use your e to pull them to you and then use your w to get the full damage off. By this time your q will be back up use it again to hopfully pick up the kill. If not yet keep basic attacking and using your abilitys till he dies.
At level 6 your ganks become rediculous. You want to engage with a q if it hits ult towards them, this will refresh the timer on you ult if they are effected by moonlight. Use your e and w to slow them and then use your ult to close gaps or finish them off.