The install instructions are the same as for any other system:
1) Set the JAVA_HOME env var to where your JDK is installed.
2) Download the JBoss AS binary. Make sure you get the binary zip file that matches your JDK - get the binary with jdk6 in the name if you are running JDK 6, get the other one if you are running JDK 5.
3) Unzip the zip file anywhere you want and make sure that the account that will run the app server has full control over the files and directories.
4) Go into the bin directory and run: chmod a+x *.sh
That's it for installation. To try it out:
5) Go into the bin directory and run: ./run.sh
6) Wait until you see a message similar to:
11:20:43,812 INFO [ServerImpl] JBoss ... Started in 29s:663ms
7) Open a browser, enter the url: http://localhost:8080. You should then see the home page.
For deploying an EAR, simply copy it to the server/default/deploy directory. For more information, read the docs.