Some quick and general Halachot in reference to the 3 weeks - aka Bein HaMetzarim.

The 3 weeks begin a period of time for the Jewish people in which many problems – mainly the destruction of the Beit HaMikdash (Holy Temple) – therefore we observe some forms of mourning during these days.

WEDDINGS: Not allowed:
Ashkenaz – from 17 Tammuz until 9 Av.
Sephardim – from Rosh Chodesh Av until 9 Av (but some follow the Ashkenaz custom).

MUSIC: (Tapes, Cd’s DVD’s, radio, etc. – includes dancing, playing or listening to musical instruments)
Not allowed from 17 Tammuz until 9 Av
On Shabbat you are allowed to sing Zemirot.

SHE’HECHEYANU BLESSING: (New fruit, new clothes, etc.)
Not allowed from 17 Tammuz until 9 Av (it’s also good to refrain on 10 Av).
Some Sephardim hold that this applies only in the week of 9 Av.

HAIRCUTS/SHAVE: Not allowed:
Ashkenaz – from 17 Tammuz until 9 Av.
Sephardim – The week of 9 Av (The Ben Ish Chai recommends to follow the Ashkenaz custom). The mustache is always allowed to be trimmed if it interferes with eating.
The rule for children is like the adults.
Women are allowed – even in the week of 9 Av (but better to refrain).

Combing hair is ok.
Nails – should refrain from trimming during the week of 9 Av (but if they are really long and protrude over the skin they may be cut even on 9 Av).

LAUNDRY: Not allowed:

Ashkenaz – from Rosh Chodesh Av until 9 Av
Sephardim – during the week of 9 Av.
Children’s clothing can be washed – but preferably a little bit at a time.
During the above dates – even wearing freshly laundered clothes are not allowed either. Therefore, one should wear their clothes beforehand for at least 10-15 minutes and set them aside for the above days.

BATHING: Not Allowed:
Ashkenaz – from Rosh Chodesh Av until 9 Av (whether hot or cold water)
Sephardim – Hot Water - during the week of 9 Av 
                  Cold Water – allowed 
                  Swimming – allowed – as long as the laws of modesty are adhered to. (Preferred to refrain during the week of).

MEAT OR CHICKEN:
Sephardim – different Minhagim (Customs)
1) From 17 Tammuz until 9 Av
2) From Rosh Chodesh Av until 9 Av
3) From 2nd Av until 9 Av
- ask your Rabbi for your specific custom.

On Shabbat meat or chicken is allowed to be eaten.

It’s good to be strict and not eat meat or chicken on the 10th of Av as well.

WINE:
It’s good to be strict and not have during the week of 9 Av – or even from Rosh Chodesh.
On Shabbat drinking wine is allowed – and for Havdalah too.