Pls Advise

Hi All,
I am more familiar with Oracle 8i Administration.
After a month i have an interview for a senior position but that post concentrates on Oracle 9ias webserver.

My friend who is recommending me has advised me to concentrate on tuning, installing, configuration. Components of it like OC4J and portals, PLSQL cartridges etc. I would like your advice on which topics to concentrate and also provide me with tips and online help if possible .
I have some general doubt like does 9i webserver come togetehr with 9i enterprise edition or is it a totally different product whihc has to be installed and configured seperately.

Pls do advise. Thanks