A woman ties a “rakhi” on her brother's right wrist, to look after him from evil manipulation and those aspects which may foul his spirit, and to fortify the bond of eternal love between them. She goes to her brother and performs the rituals by smearing on kumkum and rice particles on his forehead. In return the brother gives her an endowment and pledges to shield her too.
The 'rakhi' itself arrays from a decorated strand to elegantly ornamented balls of assorted sizes and materials such as feathery fiber, glitters, gold, silver beads and so on. Sweets symbolize the sugary moments between the brothers and sisters and on this day all kinds of sweets are prepared.
On this day, priests also fasten the rakhis on their clients and in return accept contributions from them. In several parts of the country it is usual to sketch figures on the walls of their abode and worship them with offerings of vermilion and kheer. A few parts of India also keep this day for the blessed thread changing service, when the boys abandon the previous one and slip on a new one ritualistically. However it is the emblematic never-ending union between brothers and sisters that cements ties between them even across continents, which has the most importance on this propitious day.
For more information on Rakhi, Rakhi Origins, The History of Raksha bandhan, Raksha Bandhan celebrations in India Visit - http://en.wikipedia.org/wiki/Rakhi