I read this many years ago (around 1990-92) and I don't remember a lot of details about the story.
There was a young man who was being raised by his uncle and aunt I believe. I really forget what the point of his journey is supposed to be - maybe finding his father or mother who disappeared. It was part of a trilogy, I think, and my library only had the first in the series and soon they didn't have that one either.
I remember there was a tinker that visited the cottage and repaired pots and pans. There was also some training given to the teenage hero that involved him chopping wood and it went into detail about the weight of the axe doing the work. There was also a horse and runes in the story.
The horse may have been magical or even talking. I think it was black and had a star or moon on its brow.
I think - but am not sure - that "Runes" was in the title.
I don't have any more details to give and realize this isn't a lot to go on. The writing seemed to be teen orientated but the only classification it had at my library was fantasy.