This is the first in a trilogy. The second is available and I believe the third is forthcoming, although I haven't read the second book yet. Even though it's the first in a series, Touch of Power has an ending that feels like an ending. There's plenty of work left for the characters to do at the end of this book - and in case you miss it, Snyder has the characters kind of sum it up for you in the last few pages - but there is still a good resolution of the plot points introduced in this book. So I left this story interested to read the next installment, but not feeling cheated out of an ending to this first installment. I felt the same way about the relationship between Inside Out and Outside In. The first of the books had a satisfying ending even though there were still enough plot points open (and characters I was interested in) to make me want to come back for more.
I've read a fair bit of fantasy lately and I have to say that while solidly set within the fantasy realm, this book had a very original plot and setting. Crumbling kingdoms (which we've seen before in other contexts) but very different kinds of characters with new and unusual magical powers and objectives. The heroine is a lovely blend of self-assured moral fiber and vulnerability, and the gang of blokes she's forced to travel with are all well drawn and engaging characters in their own right. Of course one of them turns out to be the love interest, but Snyder keeps us guessing which one it will be for a while which is cute.
There's nothing too explicit on the page - either gore-wise or sex-wise - which makes me say this book would be suitable for a YA and new adult audience (and probably MG as well). I couldn't actually tell who it was pitched for, although most of the characters are in their early to mid 20s which suggests YA/new adult to me. And the antagonist/general-all-around-bad-guy is kind of delicious in his self-assured evilness and his ability to manipulate emotion. This is not a book that requires deep thought. You can easily blow through it in a day or two, but it's a highly enjoyable escapist read.