Hi there.

I'm Jaycawbz, and I'd like to introduce you to the wonderful world of jungling with Lee Sin. Lee Sin is one of the best junglers in my book, as he's a safe jungler, and he can also go through the jungle at a rather fast rate. I've played Lee since he's been released, and while I am VERY inexperienced when it comes to laning with him (it's been done around 5/6 times for me, out of the MANY times I've jungled with him), so this will primarily cover jungling. I'm sure there are other guides regarding lane Lee Sin, so good luck! But, if you're still with me, let's begin here.

Pros:
AMAZING Jungler.
Almost always has a presence in the game.
Good farming.
Anti-stealth.
Strong ganks.
Not incredibly item-reliant.
You learned from Jesse Perring.
No mana!

Cons
He's Lee Sin, The Blind Monk. He has no faults!

I go with red and quint armor pen for my runes, along with yellow armor and blue magic resistance runes. Lee's a glass cannon, so we pretty much want to give him some armor and resistance starting off. It's worth it in the end, trust me. Armor isn't a big must, as our first two items end up giving us a HUGE boost in armor, but the resistance will help, as we don't get a lot of magic resistance until the very end of the game.

I go 21/0/9 with Lee, as there really isn't much difference late-game if you go with the defense masteries. If you're unsure about it, feel free to mix it up. I myself prefer the 21/0/9 tree, however. Experiment, though. When you jungle, the nine in utility should be a must. Just saying.

I've used this build for a good while, and after experimenting with a few other builds, it really helps you survive and have a presence for a majority of the game. The only problem with it is the Trinity Force, as sometimes it can set you back while not really giving you much in the areas you find very crucial. But, I find it to be an amazing item for Lee. I still don't know why.

Other than that, feel free to swap out Wriggle's late game for whatever you desire, as it is only useless after we get our bloodthirster (other than that free ward. score!) It's all situational, though. Get what you need when you need it.

I prefer to start with my W, and then go into E, Q. After that, I level up my Q to the max, and then my E. W isn't really that good outside of jungling, and leveling it up twice is usually useless, since you should have full health and a pot left after finishing your jungling route. Basically, you pretty much want it just for the first few creeps, and for the dash later game. If you really want, you could go W-E-W-Q, but I prefer ganking at 3-4. With my route, you will be level three, and ready to gank, so it's not really worth adding in another point to W.

Flurry
Flurry is a decent passive. The good thing about it is the Attack Speed that it gives. It will help you in killing off turrets faster by just shielding a creep. The energy that is given back to you is usually not noticed (or, atleast by me.) since it regains at such a rapid rate, especially with blue buff.

Sonic Wave/Resonating Strike
Lee Sin's best ability (imo). It allows him to easily chase down an enemy, and either slow them down to auto-attack the hell out of them, ult the enemy into your team; it's a really nice ability. A good trick with it is your Q-E-R combo, chasing them down, slowing them, and kicking 'em back into your team. It's pretty much ringing the dinner bell for a free kill. Another good trick is to just use your one hit of Q on it, so you can chase them, and then drop your ult on them. This will lead you right over to 'em! Good stuff.

Safeguard/Iron Will
This is a good ability for starting off. It gives you a decent amount of spell vamp, and lifesteal; also armor to boot! But, I don't like leveling it up. It's only really good for the dash in my eyes. It will save your life very often though, so don't diss it. For real.

Tempest/Cripple
Another good ability. The AoE on it is really good, and since you can slow everyone by around 60%, it's a dangerous one, too. It really assists you in lining up your ult, so don't diss it. I'm sure everyone learned about this when the double Tempest bug was up, though. Nothing more to say about it.

Dragon's Rage
Your ult. It can destroy an entire team if lined up properly, and it can also assist your team by kicking their carry into them, and even save you by kicking an enemy into your turret, or anything like that. This is actually one of the best things about Lee, since it has so much utility in it, and it can also do quite a bit of damage considering the ratios on it. A really good ultimate.

Here's what we've been waiting for!

Lee Sin's jungling is one of the best, and I'll tell you why here;

He's not too route reliant, he can start at wolves, blue, wraiths, red, etc. I can get through all of these, reach level four and still have full health with a pot left. I usually start at whatever camp closest to where I will start ganking at (example, I start at wolves, go wraiths, golems, blue, then gank the closest lane.) Route's should be experimented with, as there really isn't anyway to fail with them. For the guides sake, I will drop my average route(s).

I go with starting at the two golems, or wolves, as I find them to be the fastest routes. You can start at blue, or wherever; it's up to you. The map above shows off two of my favourite routes, and they work pretty well, as I usually finish jungling at around three minutes and fifty seconds. Note, I don't usually go for red buff, as I don't see Lee really needed it. Well, it's useful, but I feel he can pull off successful ganks without it. I only go for red when I am unable to gank anyone, as it's better than sitting in a bush for five minutes.

He's a really safe jungler, and I've heard that he's a really good counter-jungler. I've never tried it, but don't let that stop you! Leave me a comment, and tell me if it worked well for you.

Understand that in order to achieve a bigger presence, you should be contributing to ganks that are almost guranteed not to fail. Mid burn their summoners? Pushing hard too? It's almost guranteed that you can take them. Lee Sin doesn't have that much stopping him, since he has a slow, and a gap-closer. Don't go into one where they're not pushing at all. It's a waste of time. If you can, at all, lure them into the jungle. You have the ability to control the jungle with a lot of your abilities, so don't forget it.

This is my first guide here, and I'm sorry about not going too far into detail with everything, but I will update everything over time. I hope you guys enjoyed this!

TL;DR: lee sin es #1 jungler