First off, only read this trilogy if you enjoy crying. I don't but I read it anyway. Very very good, gave me nightmares for days because of how terrifyingly sad it is. It is a tale to make the angels weep, a tale to make you tremble in your covers at night, a story so sad that your pillow will need to go through the dryer on a daily basis.
I'm exaggerating, but by a surprisingly little amount. I only had to run my pillow through the dryer every other day for the next two weeks after finishing it.
I won't go into any spoilers, but it's set in a medieval world... kind of a combination between Europe and Japan actually. It's about a street urchin turned apprentice assassin basically (though if you called him that he would cut your head off because he is so much better than the average assassin that in his guild thing that is an insult) who is something not seen for ages... and he and his master are searching for a very very powerful artifact. Up until this point, it's only "mildly" sad at least by comparison (*laughs hysterically at the thought of *that* being mild*)
That's really all I can say without saying spoilers though... I thought it was a very, very good book, even as sad as it was. Once you pick it up you won;t be able to put it down. the author is very good at making it feel like *you* are Kylar Stern (the main character)