Tuesday, the 17th of Tammuz, is a fast day from sunrise to nightfall. It commemorates the breaching of the walls of Jerusalem and inaugurates
the Three Weeks period of semi-mourning for the two destroyed Holy Temples in Jerusalem.

Our first two articles discuss the spiritual causes of the destruction.
The 2nd, by the holy Ari of Safed, has a few lines of heavy Kabbalah terminology near the beginning, but once over that you should find it quite accessible.

Kabbalaonline-Shop offers a Triple-Header Prayer Special for 23 Tamuz
yahrzeit of Rabbi Moshe Cordovero.
[All donations and prayer requests must be received by Monday - July 20, 2014 Israel AM]