Flets:

The homes of the Galadhrim. Flets were platforms built in trees. Some were more complex than others, such as that of Galadriel and Celeborn.

Fang:

One of the three dogs belonging to Farmer Maggot. The other two were Grip and Wolf.

Fatty Lumpkin:

The pony belonging to Tom Bombadil. Fatty Lumpkin was a larger pony, probably between 13.2 hands and 14.2 hands if the border point between horses and ponies was the same in Middle-Earth. He was also an older pony.

The First Age of the Sun:

The First Age of the Sun. The beginning of the First Age of the Sun was when the Sun first rose, and the end, when Beleriand was destroyed in the war between the Valar and Morgoth. Other events in the First Age included the following:

The building of Gondolin
Morgoth's breeding of the race of Dragons
The Eldar meeting the Atani in Beleriand
The first of the Noldor to meet any of the Atani was Finrod Felagund and he met with the House of Bëor.
The Quest of the Silmaril
This ended with Beren wedding Lúthien and of this line came Elwing and eventually the Half-Elven and the line of the Kings of Númenor.
Nirnaeth Arnoediad, The Battle of Unnumbered Tears
Dagor Aglareb, the Glorious Battle
The Fall of Gondolin, the longest lasting of the realms of the Elves in Beleriand

This is a small selection of the events of the First Age of the Sun.

The Fourth Age of the Sun:

The Fourth Age of the Sun was the beginning of the Dominion of Men. The Rings of Power had either been destroyed or had lost their power, the Keepers of the Three and the Ringbearers had sailed into the West and a King had returned to Gondor. Aragorn, the first king of the Reunited Kingdom was crowned in the last years of the Third Age of the Sun, and died in the year 120 of the Fourth Age. This is the final Age recorded in the Red Book that we know of. The majority of the remaining Elves left Middle-Earth in this Age.

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