Her glories are sun by the poet-saint Thyagaraja in his “Sri Janakatayane”
Oh daughter of Janaka, the blessed souls of refugees! Oh Consort of Sri Raghu Rama, bedecked with shining gem-ornaments! Pray, protect me always! You are the wind that destroys the clouds of demons like the hundres-headed Ravana; You are the indweller in the hearts of the devotees; Your Feet shine with the lustre of gems set in the crown of Indra.
King Janaka was the wise and benevolent King of Janakpuri and although a great saintly king he was childless. ‘Rajarshi - a king who lives like a sage: that was how king Janaka of Videha dynasty was renowned. He ruled over the kingdom of Mithila. He looked upon his people with love and affection.
The Finding of Sita Devi in a casket in the Earth:
Janaka maharaj was ploughing a piece of land and then to prepare it for conducting a Yajna (spiritual sacrifice). He unearthed a golden casket in which he found a beautiful girl and was overjoyed. A land ploughed by the yoke is called ‘Sita’, and so he named the baby as Sita. With the arrival of the baby, the king’s good luck appeared to soar up. His queen also gave birth to a daughter who was named Urmila. The royal couple brought up the children with great affection. They gave them a good education. The two beautiful girls, by their noble qualities, good behavior and intelligence, endeared themselves to one and all and grew to become ideal princesses.
Sita grew up and played in the palace of Janakaraj. She became well known for her beauty as well as her devotion. She could often be seen absorbed in the Deity of the Lord of the Surya-vamsa. She would when on her own, sometimes lovingly enact the pastimes of the various forms of the Lord and relish His pastimes. In this way she revealed to those close to her that she was no ordinary young girl.
Her fame like her beauty became well known, and soon it was time for her to be betrothed and then married. As with kshatriya kings of those days Janakaraj organised that all the worthy kings and princes would come, there would be a challenge for her hand, and the victor would become her husband.
The story goes that one day, revered sage Parashurama came to visit king Janaka. He carried a bow with him. He left it at the doorstep of the royal hall and went inside. Sita saw the bow, ran to it and began playing with it as if it was a play-horse. Only those with great physical strength and daring could lift and handle the ‘Vaishnava’ bow. When Parashurama came out, the bow was missing. Ordinary persons could not lift it with ease and he, curiously looking around, spotted Sita playing with it as if it was a play-horse. The sage and the king were astonished.
The great Sage Parashurama, who is a partial incarnation (shaktyavesha avatara) of Vishnu then blessed Sita and said to king Janaka: “My dear king, only a great, and strong person can wed this girl of such capacity. Arrange a ‘Swayamvara’ (where the brides choose their spouses for their prowess) for her and let the most suitable person in the three worlds the marry her.”
[ Source : http://www.prabhupada.org/ ]