I recommend staying overnight on the mountain. You can take a cable car up to Huangshan. Trekking up Huangshan is estimated to take 4 - 5 hours. Frm the station to the hotel, there is a considerable walking distance of about 20-30 min on steps.
I walked down Huangshan and it took me abt 2.5 - 3 hours.
I took with me a Nikon D50, Tamron 17-50mm f/2.8, Nikon 70-200mm f/2.8 and Tokina 12-24mm f/4 in a Lowepro Orion AW. Plus a Benro carbon fibre tripod. Daypack filled with overnight change of clothes and some toiletries.
Ultra wide-angle recommended. First and second picture taken with Tokina. Third (sunrise) with Nikon. Fourth with the Tamron.