The Two Trees:

Created by Yavanna, the Two Trees were grown in Valinor. They gave out light in a fourteen hour cycle. The first cycle began the Ages of the Trees. These ages lasted until Melkor and Ungoliant killed and poisoned them. Now the only remaining sample of this light is in the Silmarils.

The Third Age of the Sun:

The Third Age of the Sun was an age of fighting against Sauron. The end of the Age was the War of the Ring and the events surrounding that war. Some of the events in this Age included:

The death of Isildur and the loss of the One Ring
The rise and fall of the North Kingdom of Arnor
The forging of the Rings of Power
The ending of the line of the Kings of Gondor
The taking of Minas Ithil:
After this, Minas Ithil was renamed Minas Morgul and Minas Anor, Minas Tirith, the Tower of Guard
The forging of the One Ring
The enslavement of the Nazgûl
Smaug's coming. The ruin of Dale and of the Lonely Mountain
The coming of the Istari:
Alatar (One of the Blue Wizards)
Pallando (The other Blue Wizard)
Radagast the Brown
Curunrír (Saruman the White)
Olórin (Gandalf the Grey, also called Mithrandir)
The destruction of Smaug and the re-taking of Erebor
The finding of the One Ring
Sauron's hunt for the Ring
The destruction of the One Ring
The sailing of the Keepers of the Three and the Ringbearers

The end of the Third Age came when the Ringbearers Frodo, and Bilbo Baggins sailed with the Keepers of the Three Rings, into the West in the year 3021 of the Third Age. Some of the events were described in the Red Book of Westmarch. Those parts published now bear the names The Hobbit and The Lord of the Rings.

The Timeless Halls:

The dwelling-place of Ilúvatar and of the Ainur before the creation of Arda. The Timeless Halls were located within the Void.

Teleperion:

One of the Two Trees of Valinor, and the elder of the two, Teleperion was the source of the flower which was formed into the Moon. From it's green and silver leaves, dripped a silver dew, which was collected. It was from this dew that Varda made some of the brighter stars. Teleperion was killed by Morgoth and Ungoliant, along with Laurelin the other of the two Trees.

Tengwar:

The tengwar letters were developed during the Ages of the Trees in Aman. Their original creator was Rúmil, but they were later reworked by Fëanor. These letters, as designed by Fëanor, were eventually spread across Arda, being used in the Undying Lands, Númenor and Middle-Earth. The tengwar designed by Rúmil have never been seen outside of Aman. Unlike the Cirth, the tengwar were created to be written with a brush or a pen, and therefore were designed with curving lines.

There were several modes of writing using the tengwar. In the most common two, the vowels were indicated by marks above the consonants. One form was more typical of Quenya writing, where the vowels were above the preceding consonant, while in Sindarin writing, the vowel was usually above the following consonant. In both modes, the vowel signs were called tehtar. In the third mode, the vowels had full letter symbols of their own. This is the form shown on the cover pages of the Red Book.

The Lord of the Rings
The Silmarillion
The Unfinished Tales
The Hobbit
The Complete Guide to Middle Earth by Robert Foster