From A Wiki of Ice and Fire
|Book(s)||A Game of Thrones (Appears)|
A Game of Thrones
He is in the same novice class as Jon Snow. Jon believes that Jeren is as weak as a girl. He is among those that Ser Alliser Thorne names as ready to become men of the Night's Watch when word is received that new recruits are on the way.
A Storm of Swords
Jeren was named to the stewards.