When is the proper time for ihram for Hajj, given that travel is on Tuesday, December 2, 2008, and does sexual intercourse invalidate ihram?

The best for a pilgrim (Hajj) and an 'Umrah performer is not to enter into the state of Ihram except from the Miqat, in emulation of the actions of the Prophet, peace and blessings be upon him, and his companions. However, if one enters into Ihram before it, it is permissible, and the ritual becomes valid. The pilgrim in Ihram must avoid the prohibitions of Ihram, such as sexual intercourse, using perfume, and wearing sewn garments. Sexual intercourse before the first 'Tahallul' (partial release from Ihram) invalidates Hajj, and it becomes obligatory to complete it and perform it again (qada'), along with sacrificing a camel. The first 'Tahallul' occurs by performing two out of three actions on the Day of Sacrifice: stoning Jamrat Al-Aqabah, shaving or shortening the hair, and performing Tawaf Al-Ifadah. If the prohibitions of Ihram occur after the first 'Tahallul', the Hajj is valid, but a 'dam' (expiatory sacrifice) becomes obligatory, which must be slaughtered in the Haram and distributed among the poor of Makkah.