Install upgrade to 2009 preferences

Am a single seat running SWX pro 2008 SP04
About to install new 2009 version.

After reading posts am a bit confused as to best method.
Should I uninstall 2008 and clean install 2009 as best method?
and install 2009 SP0 then update or download complete SP01 andinstall.
Or install 2009 in addition to keeping 2008.
I have very little cusomization and use essentially 'standard'installs.

Thanks
PaulSolidworksAdministration