I did not have the SERM for the exam (Oct. 2012), but did have the CERM. CERM was a big help for me and by far my most used book on the exam. I thought that the practice exams were very useful (both PPI and NCEES issued). I put in close to 6 months of study and felt fine during the exam.
I thought the structural depth reference manual for the PE exam was useful. I'm sure the SERM is more in-depth though I would warn you that the SERM is written for the SE exam. There's going to be info in that book that isn't for the PE exam.
I studied mostly out of the CERM and made sure I felt comfortable with the knowledge in there, but also navigating the book. I would recommend understanding the layout of your major books (CERM, AISC, ACI, ASCE, IBC), because you won't want to waste time flipping through the books when the answer is just a lookup type answer. Get some nice tabs and tab those babies up. It'll be useful later on too.
I had the PPI practice problem book that I didn't find useful.