Bak Per, (1999), How Nature Works, The Science of Self Organised Criticality, Copernicus Books
Amazon Link
Looks at Self Organised Criticality and Power Law Distributions. A good read

Barabasi Albert-Lazlo, (2003), Linked: How everything is Connected to Everything Else and What it Means, Plume Books
A good easy read about small world networks
Amazon Link

Briggs John and Peat F David, (1989), Turbulent Mirror, An Illustrated Guide to Chaos Theory and the Science of Wholeness, Harper and Rowe, New York
Amazon link
An easy to read guide, lots of diagrams and pictures

Buchanan Mark, (2002), Nexus, Small Worlds and the Groundbreaking Theory of Networks, W.W. Norton & Co. New York
Amazon Link
A good easy read on small world networks

Buchanan Mark, (2002), Ubiquity, Why Catastrophes Happen, Three Rivers Press
Amazon Link
Another great read from Mark Buchanan

Capra Fritjof, (1997), The Web of Life, A New Synthesis of Mind and Matter, Flamingo, London
Amazon Link
A very good first reader. You may also like to read his next book, The Hidden Connections, Flamingo, (2003). This book looks more at complexity in social systems.

Cohen Jack and Stewart Ian, (1994), The Collapse of Chaos, Discovering simplicity in a complex world, Penguin, London
Amazon Link
A great book going into a bit more depth.

Gleick James, (1987), Chaos, Making a New Science, Abacus, London.
Amazon Link
The ‘bible’ of Chaos Theory. The first popular exploration of Chaos Theory that still has great depth. He goes into some depth, so I would not recommend it as a first reader on  Chaos.

Goerner Sally J, (1995), Chaos and the Ecological Universe, Overseas Publishers Association, Amsterdam
Amazon Link
Great information, a bit more technical.

Gribbin John, (2004), Deep Simplicity, Chaos, complexity and the Emergence of Life, Penguin, Allen Lane, London
Amazon Link
Really great book, good wide ranging, easy to read, pictures of chaos and complexity

Gladwell Malcolm, (2000), The Tipping Point, How Little Things can make a Big Difference, Abacus, London
Amazon Link
An excellent easy read on Small World Networks and Tipping Points

Johnson Steven, (2001), Emergence, the Connected Lives of Ants, Brains, Cities and Software, Penguin, London
Amazon Link
Easy reader

Kauffman Stuart, (1996), At Home in the Universe, the Search for Laws of Self Organisation and Complexity, Oxford University Press
Amazon Link
A classic book on chaos, complextity and evolution

Kelly Kevin, (1994), Out of Control, The New Biology of Machines, Social Systems, and the Economic World, Addison Wesley
Amazon Link    Kevin Kelly’s web page

Kosko, Bart, (1994), Fuzzy Thinking, The New Science of Fuzzy Logic, Hyperion,
Amazon Link
Bart has a lot of personality that shows through and makes a mathematical book easy to read.

Lewin Roger, (1992), Complexity, Life at the Edge of Chaos, McMillan, New York
Amazon Link
Easy Reader, includes stories of the people of the Santa Fe Institute

McNeill Daniel and Freiberger Paul, (1993), Fuzzy Logic, The Revolutionary Computer Technology that is Changing our World, Touchstone, New York
Amazon Link

Progogine Ilya and Stengers Isobelle, (1984), Order out of Chaos, Bantam
This was an early classic in the field of chaos. Ilya Prigogine pioneered much of the work on dissipative systems.
Amazon Link

Stacey Ralph, (2001), Complex Responsive Processes in Organisations: Learning and Knowledge Creation, (Complexity and Emeregence in Organisations), Routledge
Amazon Link

Strogatz Steven, (2003), Sync, The Emerging Science of Spontaneous Order, Hyperion, New York
I would recommend reading other east read books before strating this to be familiar with some of the concepts raised.
Amazon Link

Taylor Mark C (2001), The Moment of Complexity:Emerging network Culture, University of Chicago Press, Chicago.
Tracing the development from, a reductionist, to post-modern to a network culture in the modern world.
Amazon Link

Waldrop M Mitchel, (1992), Complexity, the Emerging Science at the Edge of Chaos, Touchstone, New York
Amazon Link
Good easy read. Good background on the development of the Santa Fe Institute

Ward Mark, ( 2001), Universality, the Underlying Theory behind Life, the Universe and Everything
Amazon Link
A good easy read

Watts Duncan J, (2003), Six Degrees, The Science of a Connected Age, W W Norton & Co, New York
Amazon Link
Another good, easy read on small world networks