Peter...
I'll try to answer what I can as easily as can be done without sounding to windy to other who may drop in. I'll first do them in order as you asked them and then drop a note behind it. Take what you feel will help you and hope I can assist... ...
#1-California Scales... .
Unless you are running a Pre-Pass,and can follow the designated instructions that go along with them(Pre-Pass, if you do not know is a electronic box which allows you "MOST" times to pass a scale if open. HOWEVER,that is determined by axle weight as you pass over the pods in the highway or by the scale-master depending on if he has the system activated),you MUST pull into ANY scale if open no matter what state your in. Most western states also have "ports of entry" that you need to enter if they are open. Empty is just that,empty,nothing on the truck. California has a "empty" lane to bypass you by equipped with a HUGE bump to rattle your teeth and the wagon for the scale-master.
#2-Chains,if required,tend to vary state by state. Most laws require you to chain the drive axles and carry enough to chain opposite axles on the wagon. Keep in mind here you will need to learn the routes you run as they do differ and one law does not fit all,they vary state to state and even mountain pass to mountain pass in some cases.
#3-Differential locks and Power dividers are used to help with traction. A differential lock can not be engaged while moving but can be disengaged. A power divider can be engaged and disengaged while moving. Neither is rated for speeds over 40 mph and some even will kick out before that speed. Most trucks nowadays are equipped with traction control devices which are computer controlled and work much nicer than the mechanical locks. Computer assisted traction control devices are operational all the time and work even in the rain,they are the best fit once you get used to how they operate. I have been in some real nasty weather running them on our equipment and without them I am convinced it would have made the job alot harder.
#4-No idiots guides available,just the plain old drab and boring FMCSA handbook. Its got all you'll ever need to draw from.
Ok Now I will be as brief as I can...
Welcome to the most under-rated and disrespected job in our nation. We are the backbone of this nation and get the most disrespect. Laws are constantly changed to "make the industry better" all the while the BIGGEST problem with the industry is COMPLETELY ignored,the nations manufacturers/receivers. Too much of our time is wasted on loading docks loading and unloading freight which does not allow us the proper rest and causes alot of drivers to run way beyond their means to make deadlines that are insane. Trucking companies are just as much at fault as they allow big business to dictate stupid dispatches like this instead of turning it down because they know it can not be made or done. I'll leave that where I have and move on,we could write a book on most of the problems.
Trucker etiquette can not be gained by reading a book,nor can professionalism. Its gained by experience and keeping your mind open to the thought that every day is a learning experience and nothing else. When you cease to learn anything on the job,you become a danger to yourself and all the others on the road. Draw from your experiences and others who have been around the industry,never forget anything as somewhere it may help you later. When I got into this industry along time ago a old man told me this. . "Being a professional is not read in any book, its what you learn from your experiences and how you adapt it to your own job. Always lead by example and others will follow and gain from your knowledge. When you retire and feel you have done what you can to assist the industry promote safety and a good image,then you have become a professional. ". Sounds kinda corny right,I thought that too when I heard it some years ago,BUT,after 3million miles of accredited no accidents-no citations driving I am beginning to understand alot better and completely see what he meant.
I am being way to windy and will drop out with this...
Remember there are no stupid questions,your only stupid if you do not ask any. Practice safe driving habits,learn from your experiences and seek knowledge from those with experience to make your new job proceed as safe as possible. If I can help in anyway feel free to drop me a note... ... ... ... Andy
Attention: TDR Forum Junkies 
