Hi everyone !
Is French your language ? If it is so then please take note that Gentoo Québec has a guide to installation of Xfce. You may find this PDF document at this address :
As you may see, it is verion 1.00. We are currently working on version 2.00 that should be available sometimes in January 2009.
Just to mention that French guide to installation was completly rewritten by the beginning of 2011. (Funtoo GNU/Linux).