David Weber's
Oath of Swords fits all of your criteria. It's in the
Baen Free Library. The
Wind Rider CD that can be downloaded for free from
here has that and two more books from the series,
The War God's Own and
Windrider's Oath.
If you start digging through the Baen stuff, anything by Mercedes Lackey or Roberta Gellis is good if you're not turned off by occasional romance. The two often collaborate and the
This Scepter'd Isle CD has several from each author. If you find yourself liking Mercedes Lackey, her
500 Kingdoms series of books is good and is eligible for coupon codes at Kobo.
Eric Flint's
1632 series is really good if you enjoy European military history and his
Mother of Demons (on the
1635: The Eastern Front CD) is a fantastic standalone (technically SF, but a very military fantasy-type plot).
The Gauntlet Thrown by Cheryl Dyson and Xina Marie Uhl is an indie that I quite enjoyed. There are occasional grammatical errors and the formatting is a little amateurish, but nothing too distracting. It's free at
Amazon,
B&N and
Kobo. I've only read the first book, so I can't comment on the rest.
Sora's Quest by T. L. Shreffler is another
free indie that I liked, but
Viper's Creed (the second in the series) was so awful that I didn't bother buying the third. I suggest reading
Sora's Quest and pretending that it's a standalone novel.
I enjoyed the novels by Dalglish mentioned earlier, so consider that nomination seconded.