You're in luck--it's a great time to get involved in the medium. Lots of new open source multimedia platforms are available now, with great communities forming around them--making it much easy to get something up and running.
I'm not aware of any books specifically on audio visualisation, but I think you'd be well served by reading more general material on:
- computer graphics in general
- graphic design (color, form, etc)
- data visualisation
- any of the great new open source multimedia platforms
If you're writing a visualization plugin for a media player, the problem can usually be treated as mapping FFT data and time to pixel space. You get the time and FFT data nearly for free, so the remainder of the problem is graphics programming, visual design, musical sensitivity and imagination. The way you combine these will ideally be your own.
You can expect to find lots of great information, tools, examples and communities surrounding any of the modern open source multimedia platforms:
- processing.org -- a Java based platform which makes it really easy to get your works (called "sketches") up and running, with plenty of examples. You could plug in a library like minim to get the audio FFT parts for free
- openFrameworks and libcinder -- C++ based platforms. If you want to write plugins for a media player like iTunes, you may need to use a language like C++. If you already know (or want to learn) C++, both are good choices.
I'd recommend jumping straight in with a platform like processing.org, together with a library like minim, play with the bundled examples, and build your knowledge from there.
There are quite a few books on processing if that suits your learning style.
If you want to stay current, blogs like createdigitalmotion are a great resource.
Also check out artists like flight4040 and Memo Akten who are using these frameworks.
Hope that helps.
