Hi summoner!
This is my first guide, and it´s for Jinx!
You can find there runes, spells, abilities, masteries, items and counter champions.

Best support for Jinx is .
Less better is , but is good too.

I start every game with Doran´s blade, health potion and trinket. It´s normal start, but long sword and 2 health potion + 1 mana potion is another way. I dont use this start, ofcourse it´s your choice.
In early game build Infinty Sword first, then statick shiv.
Jinx is perfect mid game champion, so be active and agresive in this fase of game you must stay alive and get kills. Thats why you must finnish bloodthirster and defensive item. My opinion is Guardian Angel. This item will revive you, but it have 300s cooldown.
Late game. It´s very critical fase of game. Carry die and game is lost. But if you are a carry, you must stay with your support. No warding, no chasing, no farming at jungle and lane pushing without support! Group with team mates and say this to them:"I must stay alive, if i die we lost this game. Thats why you must cover me."

+ Very good farmer
+ Escape passive
+ High fire rate (Up to 3 stacks)
+ Global ultimate + scales with low Hp

- No escape spell
- Active q consumes mana every shoot
- W is easy to dodge and easy to spot
- Hard to master