Buy a cloth armor and 5 health pots and head to the wolf camp. Remember when jungling with Lee Sin to always space your abilities and their second effect ever two auto attacks to maximize the energy gain and attack speed from your passive. Start attacking the blue wolf spacing your e and after that finish off the little ones and pop a health pot. After you finish the wolf camp, go to the wraiths and smite the big one. Right after you smite the big one, you will be level 2 and you can level your w skill safegaurd. Remember to keep spacing your abilities and you will be fine. After the wraiths go to the two mini golems and finish them off. After this, you can wait for your wolves to spawn back up or if they have no jungler you can invade their jungle and get their wolves. Tele back to your base right after you have enough money to buy madreds razors. At this point go get both your buffs and you can start ganking if you like. At lvl 4-5 if you feel like it you can go solo dragon but i usally wait until i have wriggles lantern for the life steal and the ward to see if anyone is coming up on me so i can escape.
I know that with most junglers you start at blue buff, and you can with lee sin if you level safegaurd first, but i think that this route is better since lee sin is not the most convenient jungler in the game.

Once you have wriggles lantern, boots of mobility, and oracles elixir your job is to keep junling, but also try to gank while clearing out all the other teams wards and putting down some of your own. This gives your team superior map vision, which can be traced to easy wins and or losses if your opponents have better map vision. lee sin is a great ganker with his slow and his initiate, and is perfect for taking out low health enemies.

I can see why some people like to go dps lee sin, but i believe the tank route is better because his ablities have enough base damage on their own for a great damage output and tanking him gives him massive survivability so he can stall while his team catches up. Another great thing about tanking lee sin is that especially he can jump into 3-4 of his enemy team with thornmail use his ult to kick on of them into his team, and leave with dealing more damage than he takes while giving his team an easy kill.

This is really my first guide, so if you guys could give me some tips, that would be great.