Just took the ASTB yesterday (April 14th) and I want to give thanks to everyone that has posted in here before me.
66 OAR 9/9/8. (really happy with this score)
Study Materials
Barrons- I liked this book the most. I do not feel that the math sections were really on par with the actual exam, but they at least got me in the correct mindset.
Accepted- I wouldn't waste my time or money with this book. A handful of the problems are decent, but the book is littered with typos and mistakes that it is hard to trust as quality study material.
For Dummies- The mechanical section in this book was decent.
FAA Handbook- if you can spare the time, it is well worth the read and definitely helped me out on the ANIT
Basic Machines and How They Work- this was probably overkill for the mechanical section but it provided me with a solid foundation (having never had a physics course before.
Atrickpay's guide- Golden standard. Reviewed this many times.
Marine Gouge- Also good for mechanical concepts.
Boating safety course- This was fairly overkill for driving home a few key points of the different lights on a boat and which vessels give way and which stand on.
Various documentaries- Naval battles, WWII aircraft (know the Douglass Dauntless and other planes of that era), nuclear power, and really anything else that seemed remotely relevant.
Quizlet or other flashcard websites- plenty of good sets out there to study. (I'll see about polishing my sets up and posting them later)
Flightsim- I've been a big fan of the games for years and I suspect that it helped me somewhat on the PBM. Plus, carrier landings in FSX are fun!
AW forums- The most valuable info came from browsing these forums.
Math: I expected for the exam to start out somewhat easy and then work it's way into more difficult topics. Not for me. it jumped right in to the good stuff. I saw some probability of rolling a certain number with a pair of dice, ratio of empty space between a cylinder and a rectangular prism, exponent rules, rates, and order of operations questions. It cut me off with about 13 minutes to go and it honestly felt like I had answered about 7 questions. I thought for sure that this was going to tank my score.
Reading: Nothing new here. It's boring and two of the answers look almost identical, just very small contextual differences. Ran out of time.
Mechanical: I thought this was by far the easiest section of the 3. Most of the questions were conceptual more so than calculations as others have said. One of the questions that I didn't know was something along the lines of "How many times per second does an AC current of 60Hz change direction?" I also saw symbols for different electronic components, such as an inductor. Saw several MA questions involving pulley systems (know the differences with a fixed and moveable pulley) and inclined planes (Bob is pushing a 100lb box up a ramp x feet long with a vertical gain of y feet, how much effort, etc.).
ANIT: Know the decks of a ship, had a few questions about the poop deck and the orlop deck. Planes of the pacific theater during WWII came up. Least stressful section of the test.
UAV: Use the paper compass trick thing and practice with the flashcards. I missed one and then almost missed the following ones because I got flustered. I think my average time was probably 3.5-4 seconds per question. Could have been better, could have been worse.
PBM: My headphones were really loud with no way to turn them down so it was interesting having two people yelling in your ears

. Like others have said, do your best and don't get too worked up. The controls were largely unresponsive (especially the throttle), which results in you having to wrestle them all over the desk. I found that writing down the emergency procedures and rehearsing them a few times helped, but I found those to be pretty easy.
Thanks again AW!