Peter,
John's book was excellent in its day but there have been a number of technical developments since then. There is a lot of useful information in Dave Milbourn's article on this site: **LINK**
Browsing through some of the feature articles on this site will also provide a lot of up to date information.
There is a lot of useful information on the Component Shop website: **LINK**
Unless you are building a working submarine then 2.4GHz radio sets are the norm today and can be quite inexpensive. The come in various specification, the minimum being two channel for steering and motor control up to 6 or more for extra functions. You can get an idea of types and prices from the Howes Models website: **LINK**
This should get you started!
Colin