Hi there. This is my very first guide. I figured this out for my playstyle if this won't fit in yours then just ignore it. I try to explain my decisions and maybe give you some tips if you want to.
I am sorry if I made some spelling mistakes I'm not the best at english ^^
My playstyle is like jungle until lvl 6 with no normal ganks just when I see the enemy is getting ahead or I see an enemy gank.
I hope you like this guide and will be at least a bit helpful.

I recommend you to test the champ at the practise tool. Read carefully through the single abilities and figure out what they do. For example Diana's q give her time limited attack speed.
Another tipp is to watch some videos about this champion. Who knows maybe there is a person who can explain things better to you than me. I'm not a pro but I like to share my experience.
Ward your most important buff with a pink if you're afraid that the enemy counter jungles you.

TIPP:
At lvl 2 I use to start with my w and wait for the shield to fall down before I use my q.

I start at blue for mana reg. and cdr. I don´t use smite or a heal potion. When I am half life at gromp I use a heal potion and smite it at the end. I move over to the crab and clear it + I ward over to the enemys jungle (near mid). The next thing I do is heading the red buff. After clearing it I clear the other crab and then go back to the wolves to clear them and then go back. For the other camps I do not have enough life and/or mana. After the first back it will be much easier and you'll reach lvl 6.

TIPP:
I prefer to clear first the camps which you can not smite before changin to blue smite. If you get to low on health smite the big one.

Your build is depending on your enemy. You can play against your counters but maybe you change the build from oneshot to tanky. Against some champions like udyr you have to survive the early and try to bring the lanes ahead. You maybe go for team fights and don´t forget your cs.