i just had my checkride on monday, and a few things i shoulda studied more included the airplane's systems (being able to draw the fuel system) and lots of the small print on the sectional. the examiner, as i was warned going into my exam, likes to make the checkride a learning experience. he's been an examiner for 32 years, and he has a good idea of what to expect when it comes to where students aren't proficient. he asked me what the altitudes for an MOA were and asked me where i'd find them, then showed me why i was wrong. he also asked about local time vs. zulu time on the sectional. i know this is nitpicky, but i came out of my exam much wiser than when i entered it. on a side note, my CFI had the poor luck of walking in after my checkride, and my examiner started asking him the same questions he asked me, and my CFI got them wrong!!! the examiner went through the same explanations for him as he gave me. had to be a humbling experience.
what i did in preparation was take the written 2 days beforehand and read through the gleim private pilot book for that twice. then i read through parts 61, 91, 43, and 830 of the FAR's, as they pertained to my type of flying. i went through the pilot's handbook for my cessna 172R a few times, hitting the systems and V-speeds pretty hard. i also went through the oral exam guide two or 3 times. as for the practical stuff, i think that i put in 4.5 or so hours doing nothing but the maneuvers. if i was your students i would start at least a week early studying for these things, like i did. i passed just fine, and hopefully, with a little hard work, your students won't have a problem. and by the way, 3 hours of ground ref and shorts and softs IN ONE SITTING is hell. pure, bloody hell.