Documentation
There are several places where you can find different types of documentation for Epsilon depending on your needs and skills with Epsilon.
The cinema
For most people, the entry-point to Epsilon is http://www.eclipse.org/epsilon/cinema, which contains flash screencasts demonstrating key-languages and tools of Epsilon.
The examples
The best way to get your hands dirty with Epsilon is to have a look at the online examples, and play with them in your machine.
The book
We have put together a PDF e-book which provides a complete reference of the syntax and semantics of the languages in Epsilon. We are doing our best to keep the book up to date with developments in Epsilon but if you think you've found any inconsistencies/errors, we'd really appreciate it if you'd let us know.
The blog
In http://epsilonblog.wordpress.com we publish new and noteworthy features of Epsilon. You can subscribe to the blog using one of the free online tools (e.g. Google Reader) to stay up to date with all the recent developments in Epsilon.
Follow @epsilonews on Twitter to stay in touch with the cutting edge of development in Epsilon.
The labs
Some of the things we are working on are either too immature to include in the main release or have dependencies that conflict with EPL and therefore they cannot be hosted on eclipse.org. Therefore, we have launched a satellite project of Epsilon at Sourceforge called EpsilonLabs, where we host this sort of stuff.