Day 1: Chengdu Arrival
If you arrive in Chengdu earlier, you can visit the Renmin Park and enjoy the local tea drinking there (Heming Tea House is most famous in the park).
Visit the Jinli Old Street in the evening, and have the dinner there.
Day 2: Leshan Buddha
Take the bus getting to Leshan from the Shiyangcheng Bus Station, and visit the Leshan Buddha, and have lunch there.
Then take the bus to Emei Mountain, and stay at the foot of the Emei Mountain.
Day 3: Emeishan Tour
Hike around Emei Mountain or take the cable to travel around.
Get back to Chengdu city.
Day 4 – Day 6: Jiuzhaigou
Take the bust to Jiuzhaigou Valley, which takes about 7 hours.
Day 5: have a day tour in Jiuzhaigou;
Day 6: Get back to Jiuzhaigou.
P.S. if you are rush in time, you can take the flight to Jiuzhaigou from Chengdu, and usually, the cost is very high.
Day 7 Chengdu Departure
P.S. If you have more time in Chengdu, Qingchengshan and Dujiangyan are highly recommended, and you can visit both of them in one day if you hire a car.
I find a detailed itinerary here: http://www.chinadiscovery.com/chengdu-tours/8-days-sichuan-discovery-tour.html