Horowitz, Paul and Winfield Hill (1989) The Art of Electronics,
Cambridge Univ. Press, Cambridge, UK (second edition).
Thomas Hayes and Paul Horowitz (1989) Student Manual for the
Art of Electronics, Cambridge Univ. Press, Cambridge UK.
This book takes a practical approach to electronics, assumes you
are intelligent but may have relatively little background, and does
not swamp you with unnecessarily complex mathematics.