What you need to start with...
The actual equipment needed for a CB system is very simple - you need the CB itself, an aerial with attachment to the body of the vehicle and a cable connecting it to the set - thats about it!
Most of the CB sets available run from a 12v-14v supply - although there are 24v/12v CB's available now, which automatically sense the supply voltage and will run on 12v or 24v systems. - Ideal for 24v vehicles or if you want to use one CB for a number of machines, and swap the unit between them.
If you have a 24v vehicle, you could either go for one of these, or use a Voltage Dropper - these change 24v to 12v to allow you to run a 12v CB and/or car stereo and other 12v equipment.
The aerial is really the most important part of any system - it makes all the difference to the range you will be likely to get. As a general rule-of-thumb, the larger an aerial is, the better it will work. It should be mounted so that it is not close to any object, and has clear space around it - ideally being the highest thing on the vehicle.
We give specific farm vehicle installation advice here along with our main Installation Advice Section here, which although aimed at installing in Land Rovers and the like, is largely just as applicable for tractors and other machinery, as well as normal cars, vans and lorries.