Get Started on Debian/Ubuntu

Install scala, this would install version 2.7.7 though, 2.8.0 has just been out recently


apt-get install scala

Run the scala shell


scala

(optional) Quick upgrade to scala 2.8.0, install scala as per above and just copy the newer jars
Download scala from http://www.scala-lang.org/downloads and extract the tarball


tar xzf scala-2.8.0.final.tgz
cd scala-2.8.0.final/lib
cp scala-compiler.jar scala-library.jar scala-dbc.jar /usr/share/java

Get Started on Eclipse

Get the eclipse scala plugin http://www.scala-ide.org/ this would include the scala jar, compiler, console, etc.
When you have the plugin the following options are available

create a new scala project

right click on existing java project and add scala nature and you can now start coding both java and scala together

run the scala console inside eclipse

Reference and Links

Below are some useful reference

Scala Tutorial - useful w/ Java Background

Scala by Example - a little long, more like a scala cookbook

Programming Scala

First Steps to Scala - a bit old but still useful

Scala Idioms, Step 1, Lists and Maps - a bit old but quick way to learn about lists. Tuples are using old syntax of {x, y} which is now changed to (x, y)