Not a really master on Lee but I know some things about him.
He can go either top or jungle. Honestly, I prefer him on jungle.
Tips for jungle.
USE YOUR PASSIVE. In between each ability, always use two auto attacks.
On ganking, use your Q if you can land it directly to your enemy or save it if your enemy has any sort of gap closer. Other way is to use W to a ally minion or ally champion that it's close to the enemy. Afterwards you'll use slow (E) and use Q (if you haven't used yet) to close distance and keep dealing damage. If you have ulti, you can try to do an Insec (Q to enemy, put a ward behind, jump to the ward, ultimate the enemy to your ally) or be really sneaky if the enemy is over-extended and land Q, ultimate, second Q. You ultimate is also good for disengage so if you see someone in trouble, just W to them and kick away. The cooldown of your ultimate is short so have no worries.
Tips for laning.
As Lee, you're very strong early game. So always pick an offensive start (I recommend Doran's Blade or Fort Pot + 3 Pots). You'll win most of the trades if you play right. There's many ways to start a trade so use your abilities wisely. One of the ways is W to a minion of yours, double tap on E for the slow, get closer to your target and use some of passive stacks, get a Q in and try to deal the most damage you can meanwhile because the second activation of your Q does + damage based on enemy missing health (W -> E -> E -> Q -> damage -> Q). This is an aggressive combo but my suggestion is to save your W in case you're seeing you can't win trades or spot a possible jungle gank.
If you have your ultimate and you're sure you can get a kill: Q -> E -> Ultimate -> Second Q -> Second E -> Punch -> Ignite. That usually closes the deal. Use ward jump to close distance if needed.
Like I said, there's a lot of combos... I just said a few to get a general idea.
Some random stuff:
Recommended using smartcast (or quick cast) with Lee.
If you flash behind your target while ultimate animation is up, you'll kick behind.
Ward hopping is not easy at first times... I'll suggest you to practice that a couple of times against bots.