A review by poc
The Heralds of Valdemar: A Valdemar Omnibus by Mercedes Lackey

2.0

Clearly a first book. A whole mix of off-the-shelf tropes driven by a "Mary Sue" heroine who goes to magic school and has an intelligent horse. I barely managed to get through it and returned the rest of the series (I had bought them together in a Kindle deal). However the author is now highly successful so later works must presumably have improved a good deal, though I have yet to try any.