[Wine] linux and wine noob needs help with installing SketchUp

[rlcgrn]

I have Ubuntu 10.04 and just installed WINE 1.2 (because it's stable version).
I am installing SketchUp 8, and the installer asks what destination folder to install to.  It defaults to
 "C:\Program Files\Google\Google SketchUp 8\"
and won't let me change to the Linux format of
 "home/user/Sketchup" 
that I think is correct.  What do I do?  The Wine FAQ states:
"WARNING: Do not try to configure Wine to point to your actual Windows C:\ drive. This will break Windows and require a Windows reinstall. We have tried to make this hard to do, so you probably cannot do it by accident. If you do manage this, Wine may or may not continue to operate, but your Windows install will be 100% dead due to critical parts of it being overwritten. The only way to fix Windows after this has happened is to reinstall it. " 
 Am I understanding this correctly?
How do I proceed?