Since nobody else has replied -
There are plenty of modelling books around many of which explain radio control. Unfortunately,due to the nature of present day electronic development, every single book is out of date before it gets printed. Much the same with magazines.
The best source of information is on forums like this one. Some responses will be good, some not, but usually the dud information gets pointed out rapidly in later posts.
Currently, radio control gear is a lot like Lego - you get the bits and they plug together. It usually takes effort to get that wrong.
A bait boat will have a receiver to match the transmitter. Depending on the type, either two motors and controls (ESCs) and props for power and steering, or a single motor and a servo operated rudder. There will probably be another channel to control whatever dumps the bait.
Some makers put all of this electronicery on one board. When it is broken, it will likely stay that way.
Others use separate parts that plug into each other. It is possible to replace modules with off the shelf items. A lot depends, for you, on just what is busted.