For historical blurbs, buy a history book (though dated, In Search of Modern China remains one of my favorites).

At the risk of triggering a full-on essay in rebuttal from our resident guidebook editor, I'm going to plug Lonely Planet because I really like it. While useless with respect to things like 5-star dining, it has helped me form effective game plans in second and third tier cities many times over the years, which is a weak point for many of the higher brow guide books. A drawback that Peter has pointed out in other threads is that some content is over 20 years old (which is a substantial length of time in a country that is undergoing 8% growth). But, for the most part, it still works quite well. BTW, I also relied on LP when I was living in India during the late 90s and it was effective there as well.