This is a new updated Lee sin guide i decided to make out of boredom. This is my first guide and I do not know how to do everything to make it look like a perfect guide but I think the content is good and i hope you can learn a few new things about Lee sin.

For the runes they are petty much general ADC runes. You want to take 9 ad reds, 9 armor yellows, 9 Flat MR blues, and 3 AD quints. This gives you "Tons of Damage!" and some defense. Some alternate runes can be 9 MR per level blues if you like going for late game but i like to get my Merc treads with those MR runes and just destroy mid with the OP ganks.

The masteries are also similar to an ADC but you get 9 into defense instead of utility to just be a little more tanky and the 9 in utility just isnt that useful.

I like to start with boots 3 pots and try to gank extremely early, but if you would like you can go with cloth 5 pots and farm more and play it safe. After the boots i move onto the wriggles because it gives you lifesteal, defense, damage, and the amazing wriggles proc allowing you to clear quickly. After this I finish my boots by turning them into merc treads or ninja tabi if you really need the armor. After this I begin to work on my first major item the warmogs by purchasing the Giants belt. After this finish the warmogs and move onto the atma's impaler. Once these are both complete you will be able to tank fairly well and deal a lot of damage. After these core items there are quite a few items you can go with but it is really situational. A common purchase would be force of nature for the MR but if there is a ton of cc you should go with the Quicksilver. Some other useful items are randuins, frozen mallet, guardians angel, and aegis of the legion. If you are in a 50-60minute game with your full build go ahead and sell your wriggles and go for another major item such as a tri force.

So the first point should be put in E. This is just the quickest way to get through wraiths and red to get to level 2. Once you are level 2 put that point into Q and either gank or continue to farm if you cant find a good lane to gank. After this just max Q then W then E last. The reason you want Q first is for the insane nuke damage. Early-Mid game is where I believe lee sins damage is at its best. In a gank you will find youself doing more damage than carries because with the runes/masteries you run he basically is a carry early game. After that I max W just for better sustain and E last because its more for the slow than damage.

The summoners I usually always run are Smite of course, and exhaust. Exhaust just makes lee sin's ganks 2x better. With all of the damage your doing and the slow you already have, exhaust just makes it near impossible to escape. Another option is flash. Flash isnt recommended by many people but it can create some really good ganks in combo with his ult, but it can be risky if you mess up the ult you just wasted that and your flash. Those are the only 2 summoners I find useful, but I haven't really tried ghost on him because it doesn't seem that great.

I highly recommend Lee sin for ranked. He is in my opinion in the top 5 junglers up there with shyvana, maokai, skarner and Mundo. He is a really good pick and can even be a carry. Some junglers like maokai cant really carry a team because he is all CC ,but lee sin and a few other champs like olaf I find can carry games.

PROS
1.Very Quick jungler once he has wriggles
2.Insane early game damage
3.Good ganks if they are performed correctly
4.Tons of good skins
5.Really fun

CONS
1.May be hard at first
2.Very different from other champs
3.If you miss your Q the gank was a waste of time pretty much
4.Traditional Lee sin makes him seem emo

This section is mainly for people who have never played the champ at all. The basic route for Lee sin is wraiths>red>gank because lee sin does not need blue(manaless) and red makes ganks even better. The basic trick to jungling Lee sin is to use his passive. His passive gives you attack speed every time you use a skill. So you just E auto auto E auto auto and do the same with his W and Q. I do like to use my Q a lot for getting around the jungle so just learn the spots of the big wraith and big wolf and u can Q to them and save time.

Lee sin is a great initiater but you want to make sure you have your team ready to back you up and you also need to be pretty tanky. Once you Start a fight with your Q you want to try and focus down and ult the AD or AP carry into your team. This will do a ton of damage to the carry and make your team want to just eat him alive. After you get the carries just try and Chase down weak opponents that are escaping because Lee sin is very mobile and can use his surroundings to catch people/escape from people.

Another cool thing that wriggles does is gives you a free ward every 3 minutes. This ward can be used for normal warding on champs like shyv, but for lee sin i like to save it for use of my W. There are several things the ward and W combo can be used for. It can be used for escape, chasing an enemy who flashed, stealing dragon with Q+smite and easily jumping back over, or ganking. To gank you can place a ward over the wall W and then ult the enemy into your team. They never expect this and this is one reason why you dont need flash to gank from behind.

The combo for Lee sin is pretty simple. All you need to do is Q>>R>>Q>>E. This allows you to use Q kick the carry to or away from your team and then Q right back onto him and add the extra E nuke.

Another useful thing to do with Lee sin is to bait by using your Q flying in under a tower and then using W right back onto your team. If the enemy chases just a little they can be caught and put to death with the right ammount of CC.

Counterjungling can be easy if you do it right. Warding the enemies buffs will be a lot more useful than most people think. If you are constantly stealing blues and keeping track on spawn times it effects the entire team especially there mid if it some champ like anivia. Try not to just run into the enemies jungle and hope they dont show up before you steal there farm. To know when an enemy is not in the jungle keep an eye on the mini map a lot(which you should be doing a lot anyways). If the enemy is blue team and they are down bot ganking, rush into there blue and steal it quick. There is nobody that can really stop you besides mid and top who will never know you are in there unless they ward their own blue??? If you ever catch small moments where the enemy jungler runs past wards or shows on the map and they arent near you go for small things like wraiths if you want but they really arent too effective. The only counterjungling i find worth it is the fight for buffs.

A lot of people think its just clear the jungle and gank the near by lane. This can be true but it all depends on where wards are and how the lane is pushed. If you find the enemies warding a ton and backing off when you gank you can pick up an Oracles. Anyways, The lane you want to gank is the lane that is being pushed with the enemies overextending. This allows you to just go up behind them and gank easily making it hard to escape. Mid is a little different because there are so many ways to enter the lane in order to gank. You can still gank the pushed lane by walking around and diving because it is so easy to do on a solo carry and they dont expect it because they almost never ward areas behind them. Another way to gank both top or bot is to walk into the lanes bushes from behind but making sure minions dont get vision on you. After this just camp in the bushes until the right time and the enemy really wont expect a random jungler to fly out of a bush. Some supports really are smart and ward bushes down bot so keep that in mind.

Anytime You find all lanes are pushed or winning just keep farming up. If your mid and bot are in the right position go ahead and have everyone come in for a dragon at around level 7-8. If you have a really successful team that never needs help just focus on counterjungling and taking objectives like towers and dragon/baron. One annoying thing you find in the community nowadays is everybody expecting about 5 ganks in each lane every game and if they lose its your fault. They assume a jungler should ward their lane gank it nonstop hold it when you are across the map and do so many things. While doing these things are useful it just cant all be done for every lane. You need to balance your farming and ganking or you will get behind in gold and level. You need to be constantly on the move and trying to not waste time on ganks that cant happen.

Lee sin is in my opinion one of the most balanced junglers in the game. He is good at everything almost but not over or under powered in anything. He jungles fast, Ganks well, has a bit of CC, and does decent damage. He doesnt excell in any specific thing like Mao in CC or shyv in clearing but i think he is the perfect champ if you want a mixture of everything. If you like Lee sin I recommend looking into Shyvana and mundo because they are quite similar in terms of how they are jungled.

Here are a few youtube vids that have professional players using Lee sin to really see how to play him at his best. These videos are what taught me a lot of what i know about Lee sin. I recommend the second video the most.
Links:
http://www.youtube.com/watch?v=OuixwccO0_w
http://www.youtube.com/watch?v=rzFtMB-WYZ0
http://www.youtube.com/watch?v=FOkfHXkyIbM

I didn't watch all 3 of the videos but these are pro players so i'm sure the gameplay will be the best you can find.