Can't add much more to what jie jie and moondog have said (as usual). If you do need a guide, look up Wild China. I can't speak for their individual guides, but they put on some very reputable corporate programs and do some exotic programs in remote China. That being said, Wild China costs $$$$$$.

Otherwise, getting around in larger cities (Beijing, Shanghai etc) is not tough. Subways are well marked with signs in English and are clean and convenient. If you are staying at a half decent hotel or even a hostel, you can get directions to most places written in Chinese and take the hotel business card with you to get you back. There is so much information on China nowadays that one can easily read at least as much if not more than what you will be told by most "guides."

Now if you happen to have a distant connection or friend who is a local, that's a different story (mostly for modern life, food/shopping experiences), but that's no different from any other place and is not exclusive to China.

Please do give us more details so that we can opine/help! People here know their stuff and are ethusiastic. Chances are, a lot of the information you may be looking for is already on this forum already.