First you should be using the @EJB annotation, not the @Resource.
Second this thread http://www.jboss.com/index.html?module=bb&op=viewtopic&t=107353 shows you how to inject session beans into a JSF bean.
Have you tried doing a JNDI lookup instead of injection?
And what version of JBoss are you using? Annotation injection in servlets/JSF isn't implemented in 4.0.5 & 4.2.0.
I have been working wiht JNDI lookups for the web layer of my applications for some time, but i wanted to give a try to the JBoss 4.2 precisely because it was stated that this version was fully Java EE compliant, but aparentlly it is not
Thanks to wolf for the link but i found it not good enoguh. The actual version of glassfish supports @EJB injection of the session beans in the web layer without all the web.xml and jboss-web.xml complication
Guess i'll have to wait for the JBoss 5 version