This workbook is for programmers who are new to Prolog and who wish to write useful Prolog programs. The emphasis is on a simplified and disciplined methodology for discerning the mathematical structures related to a problem, and then turning these structures into Prolog programs. A relatively pure subset of Prolog is used and the focus is not on particular features of the language. The presentation is novel. An outline of basic concepts is interleaved with worksheets, which are graduated in scope and give guidance for practising new ideas. Extended examples in the form of case studies then apply the ideas. The book can be a useful companion to two other Springer books, as a sequel to the author's introductory text "Programming in Prolog" and alongside the reference manual "Prolog: The Standard".