Earlier this semester, one of my colleagues introduced me to the category of algorithms filed under the broad-label of "meta-heuristics". There are some excellent resources on the web, and here are two that I found really useful:
- "Essentials of Metaheuristics" by Sean Luke: It is a great introduction targeted at the "motivated-undergrad" level. The author even lets you download the book, if you fill out a simple online form for him. If you prefer, you can order a paperback for about $20.
- "Clever Algorithms" by Jason Brownlee: It is written in a very accessible tone. You can read it online algorithm-by-algorithm, or buy the PDF ebook for $11.