Sanderson is a great world-builder, one of the few modern fantasy authors who creates a world where you can imagine life going on beyond the scope of the few characters he's focussing on. While he creates interesting worlds the characters he populates them with could do with a bit more depth and subtlety. The plot of the first book is your basic "people try and overthrow the evil Overlord" story that has been done a billion times before but he pulls it off well, and gives a few quirks that play with the typical narrative of such stories. The protagonist can be a bit annoying, but in the end I found myself rooting happily for the good guys and got drawn into the story.
The good thing is the first book can sort of be read as a stand-alone so you get a pay off at the end of the first book and some closure, but if you read on the 2nd and 3rd books really expand on the first and make for a much more fulfilling story.