TP,
Unless you have a copy of Visual C++ and want to compile the Win32 binaries yourself, the "Windows Binary" distro is what you're looking for. The "Source Code" distro is just that, the source code (written in C) that compiles into the PHP interpreter and all it's various extensions. If you're planning on installing PHP onto a IIS, PWS, or Xitami server, the Windows Installer package will auto-configure those servers for you. There is no PHP configuration tool for Apache. If you download the installer package, you should be aware that it doesn't come with any additional PHP modules (GD, zLib, bzip, etc.) besides the extension which are natively supported in the interpreter (listed on the downloads page). HTH.
Cheers,
Geoff A. Virgo