I know everyone has a different opinion, and this was a top topic for me while I was studying, so here's to the new newbies:
I liked the STC for studying and the final exam practices. I used the Dearborn CD to gain some experience testing on the screen.
I read the Dearborn, but only at the end discovered the STC, which I
think is more to the point. I used the Dearborn CD extensivelly.
But at the end, just focus on the task, and do plenty of exams before the big day. good luck.