Win 7 works fine either in single HD with OS X or on separate hard drives. For simplicity and ease of maintaining the systems, I prefer to have separate hard drives.
2 drive method
1. pick an OS to install
2. connect a hard drive
3. install OS, update it, get your users set up, load your 3rd party apps, etc.
4. shutdown, disconnect cable at hd (not really necessary, but prevents you from choosing wrong drive when you select a drive to format for installing the 2nd OS)
5. connect 2nd drive to mobo
6. install 2nd OS, update it, get your users set up, load your 3rd party apps, etc
7. shutdown, reconnect the first hd
8. boot to BIOS and set the OS X hd as first in boot order. save&exit BIOS, continue boot
hit a key at Chimera screen to select an OS to boot or install Instant Menu from MultiBeast
Windows 7 boots from the System Reserved icon when installed this way unless you pre-format the hard drive with a 3rd party disc utility. With the hd pre-formatted, the system reserved partition is not created.
1 hard drive method is a little different. Either this method:
http://tonymacx86.blogspot.com/2009/11/ ... -snow.html or this method:
viewtopic.php?f=81&t=20872
will get you there.
It doesn't really matter whether you install Win7 first or OS X first, just use OS X Disk Utility to format the drive as instructed, then install either one, then the other. The downside to installing OS X first is the necessity to boot back to the OS with iBoot (or rBoot for Lion) and re-install the Chimera boot loader because Windows 7 over-wrote it Even though it doesn't use the first 440K of the boot sector, it still erases it.