There is no such thing as an "OEM single user" version of Mac OS X. There are only two types of Mac OS X Install CDs/DVDs:
1) Retail versions, which are purchased separately from a Mac computer (and come in two flavors: regular, one-computer install and 5-computer, family pack installs)
2) The bundled "System Restore" CDs/DVDs that come included with new Mac computers.
You should only have the System Restore CDs/DVDs that came with your Mac computer. Any other installs you wish to do should be done with the retail versions of Mac OS X.