In the temple God faces mostly East. Auspicious direction is East. Marriages and all auspicious functions are done facing East. Functions connected with death rituals, significantly are done with facing South.
The principal Gods/ presiding deities of each direction (called the ashtadikpalar) are:
Northeast- Eeshanya- Ruled by Lord of all quarters or Eeshwara Siva (Religions,Luck and Faith)
East- Aditya- Ruled by Sun God - Aditya (Seeing the world)
Southeast- Agni- Ruled by Lord of Fire - Agni (Energy Generating)
South- Yama- Ruled by Lord of Death - Yama (Damaging)
Southwest- Pitru- Ruled by ancestors (History)
West- Varuna- Ruled by Lord of water (Physical)
Northwest- Vayu- ruled by Lord Of Winds (Advertisement)
North- Kubera- Ruled by Lord of Wealth (Finance)
Centre- Brahma- Ruled by Lord/Creator of the Universe (Desire)
Doing japa/tapas in each of the four directions has its own characteristics. Tapas in the eastern direction gives the yogi problems and difficulties of a comparatively minor nature. Siddhi is gained soonest by doing tapas facing east. North is the best direction for ease of meditation. The yogi faces little or no problems or obstacles, enjoys good health, and experiences ananda (bliss) during meditation. The western direction is the most difficult for doing tapas and is fraught with danger. The yogi must overcome seemingly insuperable mental obstacles and endure almost unbearable physical afflictions. In addition, the yogi is subjected to several tests. Tapas to the south is a neutral direction having no particular benefit or obstacle. Meditation continues normally. There is neither ananda nor ashanti (restlessness).
Important Points About Sleeping Position:
The direction your head faces while sleeping has a strong effect on your physical and mental well-being. Head placement refers to the direction the top of your head points when lying down.
Head to South:
Benefits: Auspicious. The best position for sleeping is with the top of your head pointing to the south and feet pointing north. Brings health, industriousness and increased longevity.
Head to North:
Results: Dangerous. Never sleep with the top of your head pointing to the north and feet pointing to the south. Brings terrible dreams and disturbed sleep. You will feel miserable. Irritability, frustration and emotional instability will develop. It sucks your positive vibrations while you sleep. You will lose 50% of your willpower and your soul power will not increase while you sleep. Your physical and mental health will suffer.
(Once upon a time, the Goddess Parvathi, while bathing, placed Ganesa at the entrance of the house. She told Him not to allow anyone to enter, Lord Shiva was stopped by Ganesha at the gate. Shiva became angry and cut off Ganesha's head as He thought Ganesha was an outsider.
After knowing the truth, Shiva ordered His servants to cut off and bring to Him the head of any creature that might be sleeping with its head facing north. The servants went on their mission and found only an elephant in that position. The Lord then joined the elephant's head onto the body of Ganesha).
When starting a auspicious work. It is told to avoid looking at the following directions as the "Maru" or the god of destruction is residing in the said direction.
(based on Srilankan website)
Sundays - North (Utura) is bad
Mondays - Northwest (Wiamba) is bad
Tuesdays - West (Basnahira) is bad
Wednesdays - Southwest (Niritha) is bad
Thursdays - South (Dakuna) is bad
Fridays - Southeast (Ginikona) is bad
Saturdays - East (Neganahira) is bad
From Almanac of Tamilnadu and book 'Kalavidhanam' (423):
(Travel in day time only)
Monday & Saturday: East is bad
Tuesday & Wednesday: North is bad
Thursday: South is bad
Friday & Sunday: West is bad.