Hey everyone! This is my first guide, so I hope you like it! Let me know if you have any questions or if you'd like to leave some comments, feel free :D

Attack speed marks because Diana doesn't benefit from attack damage and attack speed will help you get your passive ability (Moonsilver Blade) more often to hit more minions as you jungle.

Armor seals for defense against champs and jungle.

Magic Resist for defense.

Ability Power for extra damage on abilities.

For Masteries, I go for all the Ability Power boosts in the offense tree (except for going with attack speed instead of cooldown reduction) and the standard jungle masteries in the defense tree. Remember that puting a point into Summoner's Resolve is important for junglers to get an extra 10 gold every time they use smite.

This guide is updated for the new 3.8 patch where junglers all around will have to change how they jungle and how their rotation goes. So keep in mind, RESPAWN TIMES FOR JUNGLE HAS CHANGED. Here is the update to the jungle as follows:

Jungle

Wolves
Initial spawn time increased to 1:55 from 1:40
Respawn time reduced to 50 seconds from 60
Wraiths
Initial spawn time increased to 1:55 from 1:40
Golems
Initial spawn time increased to 1:55 from 1:40
Respawn time reduced to 50 seconds from 60
Ancient Golem
Base Experience granted increased to 340 from 220
Now plays a particle effect to show who the buff transferred to
Lizard Elder
Base Experience granted increased to 340 from 220
Now plays a particle effect to show who the buff transferred to
Young Lizard
Base Experience granted reduced to 10 from 40

Your rotation should go as follows:

Golems
Wolves
Wraiths
Lizard
Wolves
Optional:Gank Top/Mid
Wraiths

Remember! Golems and Wolves now spawn AT THE SAME TIME. Not like they used to before where wolves would spawn before Golems. Also, MAKE SURE TO GET BLUE BUFF and as a reminder you will be level 2 after you kill golems which means you have crescent strike available, so spam that like crazy since you've got the mana to do so with blue buff.