The Tufte books are brilliant. For dynamic charts, his first book (The Visual Display of Quantitative Information) is the most relevant, it covers the theory - how to tell a good representation from a bad one - and the basics.
Apart from that, it's mostly a matter of picking up interesting ideas wherever you find them. flowingdata.com is nice, same with http://www.informationisbeautiful.net/
Readings in Information Visualization ( http://www.amazon.co.uk/Readings-Information-Visualization-I... ) is a collection of papers covering a wide range of techniques for a wide range of tasks.
Apart from that, it's mostly a matter of picking up interesting ideas wherever you find them. flowingdata.com is nice, same with http://www.informationisbeautiful.net/