Halachos of Tisha B'Av

1.  One may not wear shoes or sneakers made fully or partially of leather.
2. One may not eat from Sunset on Monday night until Nightfall  Tuesday night. (With regard to the elderly, sick, pregnant, nursing women, generally we follow the stricter guidelines applicable to the Yom Kippur fast. One must discuss this with a Rov)
3. One may not wash or bathe. (For Netilas Yadayimm in the morning or after using the bathroom one should wash only until the knuckles).
4. One should sit on the floor or on a very low seat (like an avel c'v) until Chatzos on Tisha B'Av day. (Elderly people, pregnant women, and women who recently gave birth are not required to sit on the floor).
The Peroches should be removed from the Aron Kodesh.

5. Many have the custom not to do any work or business until Chatzos on Tisha B'Av day.
6. Generally one may not learn Torah on Tisha B'Av. One may study Megilas Eicha, Iyov, Churban Beis Hamikdash, and Hilchos Tisha B'Av.
7. One should not greet another person on Tisha B'Av, all day. If one unknowingly greets you, answer curtly but courteously.
8. The custom is to not wear Tallis and Tefillin at Shachris, only at Mincha.
The custom is that one should not kiss his tzitzis at Shachris.
9. One should not smoke on Tisha B'Av. If one is unable to refrain one should wait until after Chatzos and not smoke in public.
10. Some have the minhag to sleep in an uncomfortable manner. (e.g. on the floor, or without a pillow, or with 1 pillow instead of 2).
Source:Daily Halacha