1) Between Yom Kippur and Sukkos one may not fast nor do we say Tachanun, as they are days of rejoicing, as in the days of King Shlomo they consecrated the altar when building the first temple in these days between Yom Kippur and Sukkos, and we are also occupied with building the Sukkah and preparing the four species. (Some say that Tachanun is not said until the end of the month of Tishrei.) (Kitzur Shulchan Aruch 134)
2) It is incumbent on every person to deal himself with the building of the Sukkah and placing the sechach, and even if he is an honored and important man, this is his honor. In theory one should make the blessing of Shehecheyanu on building the Sukkah, but we rely on the blessing made during Kiddush on the first night. (ibid)