A new introduction to LaTeX entitled LaTeX and Friends by Marc van Dongen has been published. The e-book is available at http://dx.doi.org/10.1007/978-3-642-23816-1 [only for subscribers]. A YouTube promotional video shows what you can do with LaTeX.
More available ebooks [only for subscribers] about LaTeX:
- LaTeX by Stefan Kottwitz (2011)
- Guide to LaTeX by Helmut Kopka (2004)
- The LaTeX companion by Frank Mittelbach (2004)