Written by Jesse Tilly and Eric M. Burke, published in 2002. http://www.oreilly.com/catalog/anttdg/, including a nifty appendix of AntPractices. There's also a lovely section in Chapter 3 entitled AINASL: Ant Is Not a Scripting Language, on why Ant doesn't do flow control, among other things.
--StevenNewton
2nd edition at Amazon: ISBN 0596006098
CategoryAnt, CategoryBook