http://www.ou.org/yerushalayim/tishabav/tishabav.htmlI found this site which explains some of the prohibitions of Tisha B'Av...
Prohibitions:
The prohibitions on Tisha B'Av itself are similar to those of Yom Kippur. In addition to not eating or drinking, we are not allowed to wash, anoint oneself or wear leather shoes.
In a prohibition more stringent than on Yom Kippur, we are only allowed to study certain portions of the Torah and Talmud on Tisha B'Av.
OBSERVANCES:
The observance of Tisha B'Av begins with the Seudah HaMafseket, the last meal before the fast commences.
NOTE: During years when the fast starts on Saturday night we do not have a seuda HaMafseket.
Unlike the elaborate feast we have before Yom Kippur, this meal is typically one course, usually consisting of a hard-boiled egg and some bread. Also, this meal is generally not eaten with others to avoid having a Zimmun (quorum for public blessing) at Birchat HaMazon. Zimmun indicates permanence, habit and durability. We avoid the Zimmun because we’d prefer not to make this mournful meal a recurring experience. It is customary to eat this meal seated on the floor or a low stool.
* Until Mincha on Tisha B'Av one should try to avoid sitting on a chair or bench. Instead, the custom is to stand or sit on the floor, just like a mourner during the Shiva (traditional seven days of mourning a loved one).
* Beginning at Mincha sitting on chairs is permitted, and we reduce the intensity of the grief that has pervaded us so far. Also, men put on Tefillin and recite those Tefillot that were omitted at Shacharit.
* It is forbidden to greet friends or acquaintances on Tisha B'Av. However, if greeted first, one should answer, but in a low tone in order not to arouse resentment.
* At the evening Ma'ariv service, the entire congregation sits on the floor and recites the Book of Eicha (Lamentations) where the prophet Jeremiah weeps the destruction, and we weep with him.
* The morning of Tisha B'Av is the saddest part of the day. We recite Kinot, and the men do not don Tefillin at Shacharit, because Tefillin are called "Pe-ar," "Glory," and this is definitely not a day of glory for the Jewish People.
The Three Weeks
This period of time is known as Bein HaM'Tzarim, "between the straits", because it says in Eicha (Chapter 1, verse 3): "and her pursuers overtook her between the straits", referring to the calamitous events that befell the Jewish people between Shivah Asar B'Tammuz and Tisha B'Av. (Some of the prohibitions and customs we observe during this period are mentioned here. For specific questions contact a Rabbi.)
* Visiting cinemas, theaters, concert halls or any other place where there is public entertainment is strictly prohibited.
* With the exception of socks and undergarments, new clothes should not be purchased.
* Haircuts are forbidden. According to some authorities, men who shave daily for business reasons may shave during this period.
The Nine Days
The intensity of the three week mourning period increases with the onset of Rosh Chodesh Menachem Av. So, in addition to those items mentioned below, during the days between Rosh Chodesh and Tisha B'Av, we are prohibited from:
* Building or performing alterations in one’s home, unless the work is important repair work. This prohibition includes painting, wall papering and other forms of home decorations.
* Eating meat or drinking wine, except on Shabbat.
* Giving clothing to or getting clothing back from the cleaners or doing laundry. Children’s clothing, especially babies and infants, may be cleaned during this period. Also, this restriction doesn’t apply to clothing warn directly against the body which requires frequent changing.
* Weaving, knitting and needle craft work, with the exception of repairing torn clothing, is prohibited during this period.
* Swimming and bathing for pleasure is prohibited. Taking a bath or shower for hygiene purposes is permitted. Children in camp may go swimming during the instructional swim period. Visiting a Mikveh when necessary is permitted.
* The Shabbat before Tisha B'Av is called Shabbat Chazon because the Haftorah that morning begins with the word Chazon.