There are two distinct mitzvot associated with Sukkot, with no immediately apparent connection
between them: the obligation to live in a sukka, a temporary booth, and an obligation to "take" four special species (and shake them). 

Why does God want us to remember that we dwelled in booths when He took us out of Egypt? What is important about remembering the desert experience in general?  What is the meaning of the enigmatic four species? And how does Shmini Atzeret fit in?

The additional joy of Sukkot derives directly from the fact that the entire holiday is an experience of being
"before God," in God's presence. Normally, this is associated with being in the Temple in Jerusalem. But on Sukkot we discover the possibility of being in God's presence anywhere, even the desert. 

6 pages
Courtesy of the Virtual Beit Midrash, Yeshivat Har Etzion