The Elves were the first inhabitants of Middle-earth and the Lands of Arda
Melkor, the Dark Lord, captured some wandering Elves, and twisted and mutilated them until they became the Orcs.
In the Second and Third Ages some Elves still lived in Wandering Companies, traveling through the broad lands they loved, but many were gathered in Elven-realms and refuges such as Lindon, Imladris, the Woodland Realm, and Lorien, were Eldarian lords ruled over Silvan populations. By by the end of the Third Age the Dominion of Men was at hand, and the Elves who remained in Middle-earth dwindled and became a secret people. Yet in Eldamar the Eldar live nigh to the Valar until the End of the World.

Elves were the fairest of all earthly creatures and resembled the Ainur in spirit. They have leaf-shaped ears, pointed relative to Men. They were about six feet tall and somewhat slender, graceful but strong and resistant to the extremes of nature. Their senses, especially of hearing and sight, were much keener than those of Men. Elves apparently did not sleep, but rested their minds in waking dreams or by looking at beautiful things. The Eldar, and perhaps all Elves, could talk directly from mind to mind without words; in other words, all Elves were telepathic.

The Elves possessed skills and knowledge that appeared as 'magic' to men.
Although they could be slain or die of grief, Elves were not subject to age or disease and were immortal. Elves could recover from wounds which would normally kill a mortal Man. However this also made the Elves less flexible in terms of adjusting to an otherwise fallen, ever-changing world.
An Elf who lost his life went to the halls of Mandos, whence he could go elsewhere in Valinor but not return to Middle-earth. The date of an elf's death is the death of the physical body. The fate of Elves is bound to Ea, and they cannot leave the Circles of the World until the End, when they will join with the Ainur in the Second Music before the throne of Ilvatar.
An exception to this was Glorfindel.

At first the Elves of Middle-earth welcomed Men, but after the treachery of the Nirnaeth Arnoediad the two races were estranged, except for the Edain and their descendants. There were three marriages between the Edain and the Eldar, and apparently others between the Edain and lesser Elves. The Elves never had much to do with the Dwarves; the hunting of the Noegyth Nibin by Elves of Beleriand and the murder of Thingol and sack of Doriath by Dwarves of Nogrod were perhaps the earliest of the many events that alienated the two races.

some important elves
*Fanor(Crafter of the Silmarils, second High King of the oldor, greatest of the Elves)
*Galadriel (Lady of Lrien, greatest Lady of the oldor)
*Celeborn (Lord of Lorien)
*Celebrimbor (forger of the Rings of Power)
*Gil-galad (High King of the oldor during the Last Alliance of Elves and Men)
*Glorfindel (elf of Gondolin that after his death returned to Middle-earth)
*Haldir (Marchwarden of Lorien) and his brothers, Rumil and Orophin.
*Legolas (also called Greenleaf, one of the Nine Walkers)
*Thranduil (also called 'The Elvenking', king of the Elves in Mirkwood, father of Legolas)
Half-Elven:
*Elrond (Master of Rivendell)
*Arwen (Queen to King Elessar also known as Aragorn)
*Elladan and Elrohir (The sons of Elrond and brothers of Arwen)

Elves discription:
Languages:Quenya, Telerin, Sindarin, Nandorin
Average height:between 6''
Skin color:White
Hair color: Black, brown, blonde (Vanyar), grey (rare of among the Sindar)
Distinctions:tall, strong, graceful, beautiful, leaf-shaped pointed ears
Lifespan:Mature at 50, Immortal

Waow! Amanda is a pro! I can clear my mind about that disturbing history now... Elf is so great, right?