Robert:
Let's review the state of the art:
PowerPC software (PPC) was written to work on the PowerPC CPU platform that Apple utilized in their Macs from the mid-1990's through 2006, when they moved to the Intel CPU architecture.
In a brilliant move that allowed all of their current user base to continue to utilize their PPC software on the newer Intel Macs, Apple licensed technology which Apple included in Mac OS X Tiger 10.4.x for Intel which they named Rosetta. It transparently allowed the PPC software to continue to run on Intel Macs. This technology continued with Leopard and was optionally available in Snow Leopard.
Apple license to include Rosetta expired with their release of Lion and now Mountain Lion. Hence those platforms will not run PPC software.
For purchasers of new Macs that run Mountain Lion, PPC software owners only have three options:
1. Update their PPC software to an Intel version, if the software publisher makes such a version available;
2. Find another modern day (Intel) application that will open their PPC software data files, modify them and then save the modified data files for future use, if such modern day apps exist; or
3. Install Snow Leopard into a virtualization program such as Parallels 8. This combination will run in Mt. Lion and gives the user access to Rosetta in Snow Leopard.
With some work, Snow Leopard client can be made to install into programs such as Parallels 8, but the current best suggestion is to purchase Snow Leopard Server, whicn can be easily installed in Parallels 8. Snow Leopard Server also automatically installs Rosetta; it is not optional.
Yes, you purchased the full Mac OS X Snow Leopard Server Install DVD. Once installed into Parallels 8, I just ignore the "Server" applications, and to make matters more simple, I remove the Server apps from the SLS dock.
So to answer your last question, installing Snow Leopard Server into Parallels 8 (and then installing Parallels Tools, as described in the Parallels instruction manual) will give you full access to most of your PPC software library on your new Mt. Lion Mac.