1. selection of data: overlay the raster data with the map you are interested in. use Arc toolbox to combine data. Reclass and Zonal are useful.
2. data analysis: projection first! (this is very important and usually ignored by economists…Parameters for China: central_meridian: 106; Stand_p1: 25; Stand_p2: 47; xian 1980).
3. use spatial analyst (not spatial analyst tools. this is always a bit confusing to me. Get it by right clicking the tool manual…)