Seam 1.2.1.GA runs ootb on JBoss 4.0.5.GA. Seam CVS HEAD runs on JBoss 4.2.0.CR2. There is currently no release of Seam that runs ootb on JBoss AS 4.2 series, so, if you want to use 4.2, you'll need to use CVS, and report bugs as you come across them.
If you are just getting started with Seam I would suggest following the getting started guide (make sure to use the JEMS installer for JBoss AS) and use JBoss AS 4.0.5.GA
There is no such thing as a CVS "load".
If you mean "check out", well it really takes quite a while.
1) Do read the docs.
2) At least when you are starting: Play by the books. Start by modifying an example. Do not change any descriptors. Do not mix-in alternative frameworks.
If you started to get a grip of everything you can always expand your app in your own way.
Is it so hard to insert single dots and question marks at the correct places - any maybe in general stop writing like an 8-year old in an IM session?