Maha Shivaratri is the day totally dedicated to the worship of Lord Shiva through day and night. Those who are the ardent devotees of Lord Shiva deem this day as the most religious and sacred in their life since it is the day very much liked by Lord himself as understood in His conversation with Goddess Parvathy.
Every month we have Shivaratri on the Chahturdasi of Krishna Paksha. Maha Shivaratri is the Shivaratri that occurs annually on the Chathurdasi of (Krishna Paksha) in the month of Phalgun (February-March). It is the day Lord Shiva grants lots of blessings to His devotees and relieves them of their sins and cycle of birth and death.
Devotees of Lord Shiva observe fast on this day and keep vigil overnight in the prayer of Lord Shiva. The next day morning they break their fast after getting the prasadam of Lord Shiva. Some of them take a tour to jyothirlingams and pay their visits to temples in veneration of the Lord.
All these legends signify the magnificence of Lord Shiva and His immense grace shown to those who pray to him ardently for relieving them from critical predicaments.
Maha Shivaratri is noted for the ascetic fasting devotees observe throughout day and night. Some devotees observe fasting without even drinking water. Others take fruits and milk while fasting. Taking a holy bath in the morning, chanting slokas of Shiva, listening to the legends connected with Shivaratri, visiting temples where special pujas for Shiva are conducted, participating in the abhishekams conducted in temples for Shiva are the important aspects of worshipping Lord Shiva on this day. There are abhishekams conducted four times (four kalams) over the night of Maha Shivaratri.
In temples, there are special abhishekams every 3 hours and devotees visit temples to partake in these abhishekams and offer milk, honey, flowers and bel leaves for abhishekams and poojas. In North India, the devotees do Abhishekam to the linga by themselves whereas in South India, the devotees have the darshan of Lord Shiva during Abhishekam and gain His grace. The next morning after visiting the temple and getting the prasadam, the devotees break their fast.
Maha Shivaratri is the day one can be absolved of his sins through ardent prayers to Lord Shiva. It also relieves him of the cycle of birth and death. Maha Shivaratri dispels darkness and ignorance from the hearts of people. It is praying by day and night and thus keeping a control over our rajas and tamas natures. Rajas nature represents our evil aspects like jealousy, anger etc. and tamas represents our inertia. By praying in the day time, we are able to control our mind and its ill aspects. By praying at night, we keep awake and are able to stay away from inertia. Thus, Maha Shivaratri is the day for dispelling our ignorance and having the fire of spiritual knowledge (as symbolised by Shiva in the form of the huge flame of fire).
In India and Nepal, Maha Shivaratri is celebrated in the most religious and sacred manner. Pashpathinath temple in Nepal, KasiViswanath and Jyothirlingams are the famous temples where this festival is celebrated in a grand manner.
So, praying to Lord Shiva on Maha Shivaratri will bring tons of benefits to the devotees as it is the day liked by Lord himself and taking part in the abhishekams in temples or doing puja at home is the way one can attain a place under the feet of Lord Shiva in Kailash.