Gnome Installation

Hi, I've recently got SUSE-9.1 package and installed it almost completely. I've left the complete gnome package. After installation, i've installed GNOMe-2,.10 from source. . Now how do i tell my computer, to pick gnome from the location. Also I want the login window to be gdm. How can i do that. How can i tell SUSE to pick gnome from the installed area. Also I'm upgrading my kde-3.2 to kde-3.4 by compilng the sources. How do i tell suse to pick kde from this new area. Thanks, Surya