[Ainulindalë: Music of the Ainur]

“There was Eru, the One, who in Arda is called Ilúvatar; and he made first the Ainur, the Holy Ones, that were the offspring of his thought, and they were with him before aught else was made. And he spoke to them, propounding to them themes of music; and they sang before him, and he was glad. But for a long while they sang only each alone, or but few together, while the rest hearkened; for each comprehended only that part of the mind of Ilúvatar from which he came, and in the understanding of their brethren they grew but slowly. Yet ever as they listened they came to deeper understanding, and increased in unison and harmony.”
― J.R.R. Tolkien, The Silmarillion

Manwë

King of the Valar, husband of Varda

Varda

Queen of the Stars, wife of Manwë

Aulë

the Smith, creater of the Dwarfs, husband of Yavanna

Yavanna

Giver of Fruits, wife of Aulë

Ulmo

King of the Sea

Nienna

Lady of Mercy

Mandos

Judge of the Dead, husband of Vairë

“Then the voices of the Ainur, like unto harps and lutes, and pipes and trumpets, and viols and organs, and like unto countless choirs singing with words, began to fashion the theme of Iluvatar to a great music; and a sound arose of endless interchanging melodies woven in harmony that passed beyond hearing into the depths and into the heights, and the places of the dwelling of Iluvatar were filled to overflowing, and the music and the echo of the music went out into the Void, and it was not void.”

Oromë

The Great Rider, husband of Vána

Lórien

Master of Dreams and Desires, husband of Estë

Tulkas

Champion of Valinor, husband of Nessa

Estë

the Gentle, wife of Irmo

Vairë

the Weaver, wife of Mandos

Vána

the Ever-young, wife of Oromë

Nessa

the Dancer, wife of Tulkas

"But now Ilúvatar sat and hearkened, and for a great while it seemed good to him, for in the music there were no flaws. But as the theme progressed, it came into the heart of Melkor to interweave matters of his own imagining that were not in accord with the theme of Ilúvatar, for he sought therein to increase the power and glory of the part assigned to himself. To Melkor among the Ainur had been given the greatest gifts of power and knowledge, and he had a share in all the gifts of his brethren. He had gone often alone into the void places seeking the Imperishable Flame; for desire grew hot within him to bring into Being things of his own, and it seemed to him that Ilúvatar took no thought for the Void, and he was impatient of its emptiness. Yet he found not the Fire, for it is with Ilúvatar. But being alone he had begun to conceive thoughts of his own unlike those of his brethren.
Some of these thoughts he now wove into his music, and straightway discord arose about him, and many that sang nigh him grew despondent, and their thought was disturbed and their music faltered; but some began to attune their music to his rather than to the thought which they had at first. Then the discord of Melkor spread ever wider, and the melodies which had been heard before foundered in a sea of turbulent sound. But Ilúvatar sat and hearkened until it seemed that about his throne there was a raging storm, as of dark waters that made war one upon another in an endless wrath that would not be assuaged."

Melkor

Morgoth, the great enemy

[The Years of the Trees]

In the beginning of days, when Middle Earth was just being shaped and before any of Iluvitar’s creation (that is, the elves and mankind) awoke, there was darkness. The two lamps of Arda were created, but soon after destroyed by Melkor. Yavanna then created and cultivated the two trees of Arda to provide light for Valar. The first tree to bloom was Telperion, also known as the White Tree. He had dark green leaves and shed silver light. He also bore beautiful white flowers. The second tree was called Laurelin, or the Gold Tree. She had golden-trimmed leaves and shed golden light. She bore fiery fruits. Time began at the blooming of Laurelin’s light, as the two trees, while wound together in fate, do not shed their light at the same time, instead waxing and waning as counterparts. The light of these trees was glorious, and it is said that the most beautiful hour to look upon is when Telperion’s light fades as Laurelin’s light emerges.

While many of the Valar were establishing their home in Arda, no light reached Middle Earth. The Eldar (or elves) awoke not to light of this world, but to the stars of Varda. They found great beauty in the stars, but they were also afraid, for Melkor was the first of the Valar to notice them. During this time, they created their first speech and enjoyed stargazing and songs, but Melkor still loomed, filling them with a general fear of any other Valar that may come, attempting to sever them from his rivals. He would also kidnap those that wandered from their group, to torture and corrupt into Orcs.

Before the Firstborns awoke, many of the Valar were becoming eager to meet other free willed Children of Iluvitar, particularly Auele. From a place of sincere but misplaced ambition, he created the dwarves in the depths of his caverns in secret from other Valar and even Iluvitar. However, Aule soon realized as he created his Dwarves that he did not have the power to grant them free will, meaning that they were bound to his will. Iluvitar saw Aule’s disobedience and demanded that he destroy them with his own axe. Just as Aule was about to destroy the dwarves, they cried out and begged for mercy. This moved Iluvitar and prompted Him to give them mercy, and He granted them true freedom of will and life. They were put in a deep slumber until after the Eldar awoke so that Iluvitar’s plan would not be altered. Thus, the seven clans awoke soon after the coming of the elves. The first of which that awoke was Durin I, father of the Longbeards clan, if you are familiar with The Hobbit.

When Oromë discovered that the Elves had awoken at Cuiviénen, great changes came about. The Valar began the Battle of the Powers against Melkor; Utumno was destroyed and Melkor brought in chains to Valinor. The Valar also summoned the Elves to dwell in their land, and many did embark on this journey to Valinor.

A period of three ages (about 2,900 years) followed. Melkor was imprisoned in the Halls of Mandos, and the Valar and Eldar dwelt together in the light of the Trees. In the darkness of Middle-earth, the Dark Elves who had not journeyed to Valinor still dwelt, and the Fathers of the Dwarves stirred. Men would not appear until some time after the end of the Years of the Trees.

These Years came to an end when Manwë released Melkor from his imprisonment. For a time, the Dark Lord pretended friendship with the Eldar, but he turned back to the darkness. After shining for 1495 Valian Years, they were destroyed by Ungoliant. During the Long Night, they stole the Silmarils and fled back to the north of Middle-earth. Seeking revenge, Fëanor led a great part of the Noldor out of Valinor and back to Beleriand.

So the Years of the Trees came to an end. At this time, the Valar made the Sun and Moon to give light to the World, and after 5000 Valian Years had passed, the Years of the Sun began. (Source: Tolkien Gateway)

[The First Age]

"The First Age, also known as the Elder Days, was the first historical era in Arda that witnessed the creation of the races of the Children of Ilúvatar, their flourishing in Valinor and Beleriand, their feats against Morgoth and his final defeat by the combined armies of the Valar, Elves and Edain." (The Lord of the Rings Wiki)