1) Anyone who is careful not to be happy during the first ten days of Av, will merit to receive the ten things that Hashem will create in the world in the future that is to come. (Kaf Hachaim 551)
2) The custom is not to bless the moon before the ninth of Av, as they are days of mourning. Instead, one makes the blessing after the ninth. (Shulchan Aruch and Mishne Berurah 426,2)
