Tisha B'av -- this year July 28 -- how is it observed?

from RELIGION & ETHICS NEWSWEEKLY:

July 28 (Begins at Sunset)

Tisha B’Av (Judaism)
Tisha B’Av is a fast day that solemnizes the destruction of the first and second temples in Jerusalem, which occurred on the same day roughly 650 years apart. This day is often recognized as the day of mourning, not just for the loss of the temples, but for other tragic events in Jewish history.
http://www.pbs.org/wnet/religionandethics/multifaith-calendar/