The Three Weeks
1. The night before shiva Asar B’Tamuz one is permitted to eat or drink until the morning or daybreak which is usually 72 minutes before sunrise. However if one sleeps a normal nights sleep, he should really stipulate before going to sleep that he will eat or drink or both when he awakens otherwise it is a question if he may eat or drink although it is before daybreak.
2. The laws of the three weeks take effect already at night. The Shulchan Aruch is of the opinion one should avoid reciting the brocha of shehechayanu during these days on new fruits, clothing etc. The Mishna Brura concludes that on Shabbos one need not refrain from saying this brocha.
3. Although our custom is not to make weddings during this time, however an engagement party, a tinaim, would be permitted even with a meal.
4. From shiva asar B’Tamuz when they broke throught the walls of the city of Yerushalyim until they destroyed our holy Bais HaMikdash three weeks later, is time for retrospection on the destruction and why the destruction. Therefore it is inappropriate to listen to music or engage in frivolous activities during this time.
5. Although there is no prohibition of conducting ones business or going to work during the three weeks before rosh chodesh, however the Biur Halacha suggests that on shiva asar B’Tamuz one should try to concentrate on the taanis and minimize his work.
6. One may certainly purchase and wear new clothing that do not require a shehechayanu, until rosh chodesh av.
7. If one ate unintentionally on the taanis, he still continues to fast and completes the taanis. Pregnant and nursing women who are able to, at least, attempt to fast, should do so. All those who eat on taanis because of reason of health etc. or small children, should not eat heavy or fancy meals but just the minimum type of meal.
8. Some have a stringency not to take a hot shower even on the other three regular taanis tzibur, of which one is shiva asar B’Tamuz.
9. The additions in davening are: a) The chazan adds anenu as a separate brocha, shacharis & mincha. b) Slichos and avinu malkenu at shacharis. c) Krias HaTora - vayichal at shacharis and mincha. d) Haftora at mincha. e) Each person says anenu at mincha as part of shomea tfila. f) The Chazan says bircas koanim and all say sim shalom in shmone esrei. g) Avinu malkenu
10. Although it is a taanis tzibur the Mishna Brura says that one who is not fasting should not say anenu.
11. If one davens together with the repetition of shmone esrei he does not say anenu as a separate brocha.

Laws of the Nine Days
1. It is our custom to refrain from eating meat or drinking wine (except on Shabbos) from Rosh Chodesh through Tisha B'Av and also until noontime of the day after Tisha B'Av.
2. If one must, it is certainly better to: a. Eat chicken, etc., instead of meat; b. Not eat freshly slaughtered meat; c. Drink grape juice instead of wine; d. Eat soup that contained meat, which now has been removed.
3. The above is in special situations. To use meat utensils for parve items is permissible.
4. A nursing mother who needs to eat meat for the sake of the baby's milk may certainly eat meat.
5. At a seudas mitzva i.e. Milah, Pidyon HaBen, meat and wine may be used (even wine for Bircas HaMazon)
6. One may eat meat and drink wine at a siyum mesichta if: a. He did not plan it for the nine days. (I.e. rush his learning to finish now)
b. He usually eats meat at a siyum mesichta;
7. The following may participate in the seudas siyum: a. Friends or relatives who would usually attend this type of seuda; b. Women who would usually come; c. The wife and children of the "baal haseuda".
8. During the week of Tisha B'Av, the number of friends that are invited should be limited to ten (aside from the participants).
9. A seudas siyum on Shabbos has no restrictions.
10. There is no restriction on other alchoholic beverages.
11. The custom of not eating meat is very strong and should not be treated lightly.
12. The Kaf HaChaim quotes sources that permit eating meat left over from Shabbos on Motzoei Shabbos for Mlava Malka.
13. The wine of Havdala is given to a child who is over five years old but not yet aware of the importance of Tisha B'Av. If none is present, one may drink it oneself.
14. To use wine in cooking or baking seems to be permissible.
15. Wine vinegar does not pose a problem.