OT: OS logo trademarked?

[RGould8 at aol.com]

If I'm creating a website for people to download my Revolution stacks, and 
I've got a Windows version and a Mac version, do I have to go through any legal 
trademark issues if I want to put the windows logo next to the windows link, 
and a Mac OS X logo next to the Mac link?   Is there an URL for both of those 
logos that shows the official way those images are allowed to be displayed to 
make them "legal"?