What is the best way of getting from huangshi city to Xisai Mountain?

From the city proper to that mountain, there is about 15 to 20km. Local bus no. 4 can take you there or you can take a taxi to reach directly!

It is hard to find good hotel or hostel in or around the mountain, except some small hostel like Shunxi Hostel.
So if time is enough, it is suggested to live in the city downtown area and take the local public bus line 4 to the attraction site. For the mountain itself, I think one day is enough.

Yes that was totally correct, I thank you very much for your help.

The distance from town to Xisaishan, Hubei, China 西塞山 and Dongfang Mountain Tourist Resort 东方山风景区 is very little. To Xisai is almost 20-30 min by bus (No4) and to Dongfong around 45-60 min (No. 11) from the East Railway station. Make sure you ask the driver to tell you where to get off - there are no signs or anything, or at least we wouldn't have been able to spot the place on our own. (In my opinions they are not really mountains... just some bigger than average hills, very easy to get to the top and both accessible by car)

Entrance fee for Xian: 10Y and for the temple at the top of Dongfang is 20Y. (30th of March 2014)

We stayed at a hotel very close to the east railway station, there are many others in that area. (158Y for a double room)