With this build you will be able to do very good dmg and still be hard to kill (you will come out with round about more then 300 ad, 3500hp and 120 armor and mr! Enjoy!

In my opinion Lees biggest strengh is his high mobility.
As his other stats are pretty average this is the one thing i focus on when palying as Lee.
As you will never be quite tanky and wont deal this much dmg late game, you want to do 3 things to maximise your effectiveness:
1. Gank a lot
2. (depending on the enemie jungler) Counterjungle a lot
3. Get farm

As a jungler, you have got to do your best to help your mates to win their lanes (and yes i know they can suck (but dont tell them) and yes you cant win their lane and yes its not your fault if they loose your lane 1 v 1). So ensure to gank the lanes that need it. I usually finish my 1st Jungle rout (red, wraiths,wolves, blue) and perform my 1st gank (depending on the Situation : bot or top). Obviously you should gank a lane that fall behind (this early) as fast as possible even if that means loosing some early xp. So dont go for strict farming, doing 1 gank (after all camps are cleared) and go back to farming. Try to think how the other team might think!
You want to be the hidden monster in the fogg of war, the thing under their beds, that prevents them from sleeping! And a monster whoms actions are obvious isnt scary!
So dont loose your flexibility!

Lee is a great counter jungler! He has his insane Sonic Wave and two flashes (the normal flash + the wardjump). And his cleartime is good aswell.
But the most important thing about counterjungling is the ability of the player. You have to think as their jungler, analyze every movement your enemies do and react individually on everything that happens!
You finished your buff the wraiths and the wolfs (you hit level 3), all the enemies besides the jungle-rengar are in lane?
Go catch him at his blue!

This depends very much on the enemie jungler. So ask yourself the following questions before counterjungling:

Where is the enemie Jungler (Was he already seen, where did he gank last, what itmes did he have)?
What is the enemie jungler for a type of jungler (does he have sustain in jungle like fiddle, or does he get low on health like rengar)?
Where are the Laners ?
Could i beat the enemie JUngler 1 v 1 with getting away with more then 33% of my health and not burning my escapes?

Last but not Least: Never counterjungle Jax.

You need to get your farm, so dont go top when the lane is pushed, just to show presence.
And dont run bot if they need help ,when you are currently on toplane.
See it like a rope: For a rope to be strong you need to mix stripes of jarn.
1 is the ganking and the 2. is your farm!
If you dont got farm your ganks arent as good as with farm!
SO try to clear atleast 1 camp every time you enter your jungle, before ganking (expect you can countergank)

wriggles gives good clear speed, but the attackspeed is a little wasted.

Pls tell me your opinion about this guide (ill add more explanation later)!