Someshwar is one of the numerous names of Shiva. Shiva is often portrayed as adorning the crescent moon on one side of his forehead. This symbolizes Shiva as the master of the Universe; the origin of the Hindu Lunar calendar. The Hindu Lunar calendar is based upon the various phases of the moon and hence Shiva is in the ancient Indian tradition as the all encompassing Kaal or Time.
Someshwar also symbolizes peace and bliss as the moon is associated with mental peace. The name Someshwar has also been associated with the famous Indian temple Somnath; in the state of Gujarat.
A special Soweshwar Yantra is prepared to worship Shiva; as the origin of bliss and peace. The Yantra is prepared on copper and worshiped by offering white flowers, incense and the lighting of a Diya. Milk and Rock Candy are offered as Prasad.
The specific mantra of Someshwara which I have given here is chanted for one Mala or 108 chants while worshipping this Yantra.
This worship is aimed at mental peace and bliss as also success in worldly life; including accumulation of wealth and property.