I absolutely loved the first book of this trilogy, Shaman's Crossing, but Forest Mage was a disappointment. The plot of the book is this: "the magic" (which seems to be a sentient being of such power that it's not clear why it requires human help) shoves the protagonist, Nevare, across the country of Gernia until he reaches the Speck forest. It does this by screwing up his life until he has no other options. What really bothered me about this plotline (aside from the fact that, in the context of the trilogy, it's little more than a "bridge book" getting us from Point A to Point C) is that Nevare has no free will. Whenever he tries to assert himself, his situation gets worse. And nothing that goes wrong (even his own sudden obesity) is his fault. It's gone from very easy to relate to his problems in book one, to almost impossible here. If I'd realized after finishing Shaman's Crossing that the rest of the trilogy would be an exercise in determinism, I'm not sure I would have continued at all.
There are some positives in this book: both the world and the characters who inhabit it remain three-dimensional and fascinating, and Hobb's writing style is still good. It is overlong, though; I can't imagine why the publishers thought it was necessary for this installment to be 150 pages LONGER than the first book, and the excessive length plus numerous grammatical, continuity and other minor errors made me think it was a rush job. And it's hard to spend this much time reading about a protagonist who spends most of his time on his own. Supporting characters tend to appear for chunks of the book, then disappear again; there isn't a single one who is present throughout, although many of them are far more interesting than Nevare at this point.
Hate to say it, but I would recommending stopping after book one.