Gaelm has told you that in exchange for doing tasks for the Stable-masters of Bree, he will grant you the boon of being able to ride one of his steeds. Although lacking the power and stamina of his father's horses, Gaelm's horses are more tame and easier to ride.
'Have you come seeking a steed of your own? I may be able to help you. My father is teaching me to become a Horse-master in my own right someday, but currently the horses I breed lack the stamina his possess. However, they are more tame than my father's horses, so you should be able to ride one, if you so wish.
'I will grant you this boon, though, only in exchange for helping me. My father has made an arrangement with the Stable-masters of Bree. Instead of refunding their money for horses that have proven unusable in their trade, he has offered to do work for them. These tasks usually fall to me, but if you do some of these tasks for me, I will allow you to ride one of my steeds.
'The first task is to bring a sack of grain to Bill Rosewood at the stables near the West-gate of Bree. The grain is over to the east, by the silo.'
The sack of grain is near the silo on Hengstacer's Farm, east of Gaelm.
Gaelm has instructed you to pick up a sack of grain near the silo at Hengstacer Farm and bring it to Bill Rosewood, the Stable-master near the West-gate of Bree.
Bill Rosewood is at the stables near the West-gate of Bree, to the south of the Hengstacer Farm.
You should speak with Bill Rosewood at his stable.
The Boar Fountain is south of The Prancing Pony Inn in Bree.
Bill Rosewood has asked you to draw water from the Boar Fountain in Bree and use it to muck out one of his stalls by the West-gate of Bree.
Bill Rosewood is at the stable near the South-gate of Bree.
You mucked out one of Bill Rosewood's stalls, but he mentioned that Bert Goldenleaf, who maintains the stalls by the South-gate of Bree, may need the same service. You should speak with Bill Rosewood again before you leave.
The Boar Fountain is south of The Prancing Pony Inn in Bree. Bert Goldenleaf is at the stable near Bree's South-gate.
Bill Rosewood told you to draw some water from the Boar Fountain in Bree and use it to muck out one of Bert Goldenleaf's stalls.
Bert Goldenleaf is at his stable near the South-gate of Bree.
You should speak with Bert Goldenleaf to see if there is anything else he would ask of you.
Return to Gaelm at the Hengstacer Farm in the Bree-fields, north of Bree.
You have done all that the Stable-masters of Bree have asked of you. Now you can return to Gaelm and see if he will allow you to ride one of his tame mounts.