The above article discusses the different types of hydrangea. Each type is different and pruning them at the wrong time of year will result in no blooms.They like dappled shade or morning sun, afternoon shade.
If it is a newly planted shrub, it will require more water than an established one. This has been an exceptionally dry summer. Plants need to be watered deeply (maybe eight inches down) infrequently (once a week). The key is consistently moist, well-drained soil.
I am also sending you information on disease identification. http://extension.psu.edu/pests/plant-diseases/all-fact-sheets/hydrangea-diseaseshttp://