Ilúvatar and the Ainur
Its seems to me that the information on Eru (Ilúvatar) is fairly limited as with the Ainur so I have decided to help cerain people who ge lost when these names are mentioned a little help by telling you all who everyone is.
Eru (Ilúvatar/the Flame Imperishable) Is the god of Arda (Middle Earth and the Unding lands)
Eru created the Ainur who where immortal spirits or gods.When the enterd Arda they split into two groups.The Valar(15 of them) and the Maiar(alot of them but only a few are mentioned).The Valar are the senior gods the Maiar the lesser.
The Valar.
Manwé,King of the winds
Varda Queen of the stars
Ulmo,lord of the Oceans
Nienna,the weeper(?)
Aulé,the smith
Yavanna,giver of fruits
Oromé,lord of the Forests
Vána,the youthful
Mandos,keeper of the dead
Vaire,the weaver
Lórein, Master of Dreams
Este the Healer
Tulkas,the wrestler
Nessa the dancer,
Melkor(Morgoth), the Dark Enemy.
The Maiar (the Most Important ones only,soz)
Melian,Queen of the Sindar
Arien,the sun
Tilion,the moon
Sauron,the ring lord
Gothmog,lord of the Balrogs
Ungoliant,the spider
Goldberry the river daughter
Iarwain Ben-adar (Tom Bombadil)
The Istari or five wizards are also of the Maiar they are...
Curunír,Saruman the White
Olórin,Gandalf the Grey
Aiwendil,Radagast the Brown
Alatar and Pallando,the Blue Wizards.