The Baker's Boy will never win any awards for originality, but neither will any other fantasy novel -- they're basically all Tess of the D'Urbervilles with more magic, and fewer sweating peasant girls. The parallels with The Belgariad, Assassin's Apprentice, The Dragonbone Chair, etc. are obvious, but unimportant.
What this book does have is plot, pace and humour. It's never boring and often amusing. The humour is genuine, and integrated into the narrative; not a bolt-on extra like the sardonic interchanges between characters slipped into the interstices of the plot as favoured by Eddings.
This, Ms. Jones achieves by some nice writing. Firstly, she hasn't gone for the "show, never tell" business -- when "tell" works better, she's happy to tell. Then there's the clever use of the castle guards, Bodger and Grift -- their ribald conversations are amusing, and necessary-but-boring parts of the story are quickly covered by an after-the-fact discussion between these two characters.
Tricks like introducing any section involving Tavalisk with a description of the meal he's just finished eating, and filling in Tawl's back-story bit-by-bit as the book progresses also add humour, tie the novel together, and add depth without becoming dull.
Although I'm no expert on the technicalities of writing, this book manages to feel extremely competently constructed, giving confidence that it's not going to disappoint later on. All the way through, I felt like Ms Jones knew where she was going. This is something that Robert Jordan, for example, never managed to achieve.