Sean Luke: Essentials of Metaheuristics
"Metaheuristics" is calculation technique for obtaining optimal solution which gives minimum value (or maximum value) of the function with large number of variables. The features are to carry out the search while mutual relationships are given based on the experimental rule in respect of the multiple points." (Sciencelinks.JP)
Essentials of Metaheuristics is an easy to understand book that features lecture notes about metaheuristic algorithms. Written by Sean Luke, the book is available as a free PDF download and intended for helping out undergraduate students gain a better insight about the subject.