You will get a lot of information if you buy The Complete Spectrum, published by Granada and edited by Allan Scott, a conglomeration of articles by authors such as Ian Sinclair, Mike James, and S M Gee.
The seven sections include information about setting up the computer, Basic and machine code, writing games programs and getting the most from peripherals.
Not satisfied with producing information about all aspects of the machine the publisher and editor have made it easy for the reader to find any information which is needed from hardware and software suppliers. An appendix listing most Sinclair supporting companies is a boon to any reader who might come across a reference to such companies in a magazine which then omits to mention its address. The software appendix even lists some of the most famous games on the market.
For a paltry £10.00 The Complete Spectrum is excellent value for money. One word of warning, though, to people who have bought any other Granada books on computers. Much of what is in the compilation has been culled from those books so beware. There had to be a catch somewhere.