The Rohirrim:

The people of Rohan. The land of Rohan was given to Eorl the Young in reward for their aid in the Battle of the Field of Celebrant. For Eorl and his men arrived just in time to save Gondor from losing the battle.

The Rohirrim were amazing horse-breeders and horsemen. Always they were allies of Gondor, aiding her when they were able.

Rhymes of Lore:

The Rhymes of Lore were a way of remembering old facts. The only one recorded was (LOTR.620):

Tall Ships and tall Kings
Three times three,
What brought they from the foundered Land
Over the flowing sea?
Seven stars and seven stones
And one white tree.

Pippin said that Hobbits have their own rhymes of lore, so it is likely that each people or culture had their own set.

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