Like Doc.NO said, just download the full Beta 4 EXE, I know it's big, but just leave it overnight or something. This will do everything automatically and insures that everything installs correctly, just click on "Front Page" tab above, follow the page down till you get to the Jaws video, under this video are the downloads, you want the 4th one down. By the way, what's your operating system and computer spec's? Also check Half Life 2 first to see if that works OK, if that doesn't that could be your problem.
Basically, this is what I did:-
1. Downloaded and installed Steam
2. Created a Steam account
3. Purchased Half Life 2 on Steam and installed
4. Installed Source SDK Base 2006 & 2007
5. Installed the Goldeneye Source Beta 4 (Automatically installs to the correct folders)
6. Double clicked the Goldeneye Source shortcut and played the game.
It should be that simple really. My specs are:-
OS: Windows 7
CPU: AMD Athlon Dual Core x2 4200+
RAM: 2Gig DDR
VID CARD: Nvidia Geforce 8600 GTS 512MB
Going by these spec's, my computers out of date, but I still run it with highest settings easy.
Hope this helps, if not just ask, but don't forget to mention your spec's.