I think you can consider moondog 's suggestion if you know where you want to go. I've done local guides throughout China and the quality is really a spin of the roulette wheel.

I've had to spend weekends in Baotou and Hohhot and wanted to do something customized and off the beaten trail. The physical travel agencies and hotels (Shangri-La in both cities) were no big help, their clientele want the tourist bus package going to the same places as everyone else.

What worked for me in Hohhot was talking to a hotel doorman who was a local (born in Hohhot) who knew a taxi driver who would take me anywhere I wanted for a day for 500 RMB. The concierge was from Beijing and, frankly, useless other than the usual top 5 places to see around Hohhot and bus tours. Got to spend a day exploring the 7-monastery complex I found on google earth which, while not exactly open to the public, allowed me to walk around at will. On a different trip to Baotou I did the same to see some remote sections of the Great Wall and another monastery.

The hotel doorman in Hohhot also gave me a suggestion for a restaurant which locals use when they want to have a small celebration like a birthday. It was one of the best restaurant experiences I ever had in China. I liked the dipping spices for the roast mutton so much but they would not give me the recipe so they gave me a bag of it to take! Great place.