Installing 64bit debian, encountering issues

Like many, I am relatively new to linux. A few years back I used a version of Mandrake for quite some time. I'm interested in trying linux again, and have downloaded debian and ubuntu installs. My I downloaded the most recent "unofficial" 64 bit debian distro. The installation goes well, although the second disc is never used. At one point the installation asks for a second disc, but then doesn't actually use the second disc for anything. The installation finalizes, and restarts, and I'm presented with a command prompt. I was never asked which window manager to install, and I don't know how to start one from the command prompt. I wasn't prompted to install any packages during the process, though, that may be a feature limited to mandrake. So, basically, I install the OS, but I don't have a gui. Any help would be greatly appreciated! keep in mind, I'm new. Thanks in advance!