I started with the book from
http://www.backyardaquaponics.com/
it is an OK read. It definitely covers the basics and is a good intro, but really doesn't go into any great depths. It is also a bit expensive for what it is.
I ordered the book before this forum started and have found it is much easier to ask a question in a place like this and use the general consensus as a guide. Having said that, it helps to understand the basics before you start.
If nothing else, i would recommend starting a small system (i.e. as small as a fish tank and a grow bed above it, or if you are a bit more adventurous, even a small water tank or equivalent (i saw a 900L bucket style one at bunnings for $150. It had a lid and would make a great pond.). I am all for recycling, so those blue barrels you see at produce stores have been used before and are a cheap place to start.
I am by no means an expert, but i would be interested to see how other people got their start, or at least gathered their knowledge base