Shabbat begins the 9 Days leading up to Tisha B'Av. The operative principle at work during this period is, "When Av commences, joy is lessened" (Talmud Taanit). We decrease our involvement in business matters, building, recreational activities, etc. to lessen pleasure (& mark the cessation of our Korbanot in the Bet HaMikdash). All those over age 6 customarily abstain from meat, poultry, wine or grape juice, except on Shabbat or at a Seudat Mitzva (e.g. siyum, Brit, Pidyon HaBen, etc). Beer & whiskey, however is allowed. Food that is cooked in fleishig utensils may be eaten. We avoid purchasing or laundering clothes; or wearing freshly-laundered clothes, if possible (other than on Shabbat). Underwear, socks & young children's clothes MAY be laundered. Bathing for pleasure is not allowed; but we assume that bathing/showering today is for hygienic purposes & so it is permitted. Swimming, unless it is instructional, is avoided for those above Bar/Bat Mitzva age. Pleasure trips & gift-giving should also be avoided.

(Note that this is Ashkenazic custom; most Sefardim only observe these semi-mourning practices in the week when Tisha B'Av occurs, which doesn't happen this year at all, as 9 Av is on the first day of the week.)