I'll second the SEAOC manuals. I worked through all the problems in Volumes 1 and 3. I also read all the code sections referenced by those problems and used them to highlight and/or tab specific sections and "wrinkles" to look out for on the exam.
I also bought and worked through most of the problems in Alan Williams, "Structural Engineering PE License Review Problems & Solutions, 8th Ed.". A lot of the "mistakes" in the solutions turned out to be mistakes on my part. The problems in this book seem pretty difficult at first go, but I think if you study the solutions and work through them, they really prepare you for the types of problems you'll see on the exam. Not only are the problems all taken from old PE and/or SE exams, but each problem is referenced as such. There is another Alan Williams book called, "Seismic and Wind Forces: Structural Design Examples" that is worth a look. The fundamental material is pretty good. I ran into several legitimate errors in the steel design section, but if nothing else, the problems in this book will expose you to more situations and hopefully, broaden your comfort zone when it comes to the much more limited number of problems on the exam.
Also, I worked the NCESS sample exam and the PPI sample exam several times. THe PPI sample exam is buildings only, so keep that in mind. Beginning about a month out from the actual exam, I worked the essay portions with a stopwatch over and over. I took the AM exams under time twice each and I should note that I failed the multiple choice exams all four times (IIRC). But there is no better preparation than to work problems in the exam environment. I will note that the NCEES essay solutions seem to be minimum passing solutions. Meaning, the solution presented is the minimum amount that would qualify a candidate for an acceptable essay answer. The PPI sample exam includes much more thorough essay solutions. And, of course the caveat with the essays is that they are graded by humans and the criteria are unknown. The best gouge for essays seems to be demonstrate your engineering judgment and problem solving ability regardless of how comfortable you are with the "nuts and bolts" of the exam, i.e. - in my opinion, an inelegant, but serviceable solution seems likely to win the candidate more points than a flurry of code references and an incomplete, or unserviceable solution.
I'd be happy to elaborate or share more if anyone reading this is interested. Best of luck to everyone, it's quite an accomplishment to qualify to sit for these exams, and as the passing rates indicate, it's a significant accomplishment to pass. Congratulations to all.